draft-ietf-softwire-lightweight-4over6-deployment-00.txt   draft-ietf-softwire-lightweight-4over6-deployment-01.txt 
Network Working Group Q. Sun Network Working Group Q. Sun
Internet-Draft C. Xie Internet-Draft C. Xie
Intended status: Informational China Telecom Intended status: Informational China Telecom
Expires: July 29, 2017 Y. Lee Expires: January 4, 2018 Y. Lee
Comcast Comcast
M. Chen M. Chen
FreeBit FreeBit
T. Li T. Li
Tsinghua University Tsinghua University
January 25, 2017 I. Farrer
Deutsche Telekom AG
July 3, 2017
Deployment Considerations for Lightweight 4over6 Deployment Considerations for Lightweight 4over6
draft-ietf-softwire-lightweight-4over6-deployment-00 draft-ietf-softwire-lightweight-4over6-deployment-01
Abstract Abstract
Lightweight 4over6 is a mechanism which moves the translation Lightweight 4over6 is a mechanism for providing IPv4 services to
function from tunnel lwAFTR (AFTR) to lwB4s (B4s), and hence reduces clients connected to a single-stack IPv6 network. The architecture
the mapping scale on the lwAFTR to per-customer level. This document is similar to DS-Lite, but the network address translation function
discusses various deployment models of Lightweight 4over6. It also is relocated from the tunnel concentrator to the tunnel client, hence
describes the deployment considerations and applicability of the reducing the amount of state which must be maintained in the
Lightweight 4over6 architecture. concentrator to a per-customer level. This document discusses the
applicability, describes various deployment models and provides
deployment considerations for Lightweight 4over6.
Status of this Memo Status of This Memo
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Deployment Model . . . . . . . . . . . . . . . . . . . . . . . 4 2. Deployment Models . . . . . . . . . . . . . . . . . . . . . . 4
3. Overall Deployment Considerations . . . . . . . . . . . . . . 6 2.1. Top-Down Deployment Model . . . . . . . . . . . . . . . . 4
3.1. Addressing and Routing . . . . . . . . . . . . . . . . . . 6 2.2. Bottom-Up Deployment Model . . . . . . . . . . . . . . . 5
3.2. Port-set Management . . . . . . . . . . . . . . . . . . . 6 2.3. Campus Deployment . . . . . . . . . . . . . . . . . . . . 5
3.3. lwAFTR Discovery . . . . . . . . . . . . . . . . . . . . . 7 3. Overall Deployment Considerations . . . . . . . . . . . . . . 5
3.4. Impacts on Accouting . . . . . . . . . . . . . . . . . . . 7 3.1. IP Addressing and Routing . . . . . . . . . . . . . . . . 5
4. lwAFTR Deployment Consideration . . . . . . . . . . . . . . . 8 3.1.1. IPv4 Routing . . . . . . . . . . . . . . . . . . . . 5
4.1. Logging at the lwAFTR . . . . . . . . . . . . . . . . . . 8 3.1.2. IPv6 Routing . . . . . . . . . . . . . . . . . . . . 6
4.2. MTU and Fragmentation Considerations . . . . . . . . . . . 8 3.2. lwB4 Configuration . . . . . . . . . . . . . . . . . . . 6
4.3. Reliability Considerations of lwAFTR . . . . . . . . . . . 8 3.2.1. DHCPv6 Based Provisioning . . . . . . . . . . . . . . 6
4.4. Placement of AFTR . . . . . . . . . . . . . . . . . . . . 9 3.2.2. DHCPv4 over DHCPv6 Based Provisioning . . . . . . . . 7
4.5. Port set algorithm consideration . . . . . . . . . . . . . 9 3.2.3. PCP Based Provisioning . . . . . . . . . . . . . . . 7
4.6. Path Consistency Consideration . . . . . . . . . . . . . . 9 3.2.4. NETCONF/YANG Based Provisioning . . . . . . . . . . . 7
5. lwB4 Deployment Consideration . . . . . . . . . . . . . . . . 11 3.2.5. Other lwB4 Configuation Considerations . . . . . . . 7
5.1. NAT traversal issue . . . . . . . . . . . . . . . . . . . 11 3.3. lwAFTR Discovery . . . . . . . . . . . . . . . . . . . . 8
5.2. Static Port Forwarding Configuration . . . . . . . . . . . 11 3.4. Impacts on Accouting . . . . . . . . . . . . . . . . . . 8
6. DS-Lite Compatibility Consideration . . . . . . . . . . . . . 12 4. lwAFTR Deployment Considerations . . . . . . . . . . . . . . 8
4.1. Logging at the lwAFTR . . . . . . . . . . . . . . . . . . 9
4.2. MTU and Fragmentation Considerations . . . . . . . . . . 9
4.3. Reliability Considerations of lwAFTR . . . . . . . . . . 9
4.4. Location of lwAFTRs in the Network . . . . . . . . . . . 10
4.5. Path Consistency Consideration . . . . . . . . . . . . . 10
5. lwB4 Deployment Considerations . . . . . . . . . . . . . . . 11
5.1. NAT Traversal Issues . . . . . . . . . . . . . . . . . . 11
5.2. Static Port Forwarding Configuration . . . . . . . . . . 11
6. DS-Lite Compatibility Consideration . . . . . . . . . . . . . 12
6.1. Case 1: Integrated Network Element with Lightweight 6.1. Case 1: Integrated Network Element with Lightweight
4over6 and DS-Lite AFTR Scenario . . . . . . . . . . . . . 12 4over6 and DS-Lite AFTR Scenario . . . . . . . . . . 12
6.2. Case 2: DS-Lite Coexistent scenario with Separated AFTR . 13 6.2. Case 2: DS-Lite Coexistent scenario with Separated AFTR . 13
7. Acknowledgement . . . . . . . . . . . . . . . . . . . . . . . 14 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 14
Appendix 1. China Telecom Experimental Result . . . . . . . . . . 18 Appendix A. China Telecom Experimental Results . . . . . . . . . 17
1.1. Experimental Environment . . . . . . . . . . . . . . . . . 18 A.1. Experimental Environment . . . . . . . . . . . . . . . . 18
1.2. Experimental Results . . . . . . . . . . . . . . . . . . . 19 A.2. Experimental Results . . . . . . . . . . . . . . . . . . 19
1.3. Conclusions . . . . . . . . . . . . . . . . . . . . . . . 20 A.3. Conclusions . . . . . . . . . . . . . . . . . . . . . . . 20
Appendix 2. Tsinghua University Experimental Result . . . . . . . 21 Appendix B. Tsinghua University Experimental Result . . . . . . 20
2.1. Experimental Environment . . . . . . . . . . . . . . . . . 21 B.1. Experimental Environment . . . . . . . . . . . . . . . . 20
2.2. Experimental Results . . . . . . . . . . . . . . . . . . . 22 B.2. Experimental Results . . . . . . . . . . . . . . . . . . 21
2.3. Conclusions . . . . . . . . . . . . . . . . . . . . . . . 22 B.3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . 22
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 22
1. Introduction 1. Introduction
Lightweight 4over6 [I-D.ietf-softwire-lw4over6] is an extension to Lightweight 4over6 [RFC7596] (lw4o6) is an extension to DS-Lite
DS-Lite which simplifies the AFTR module [RFC6333] with distributed [RFC6333] which simplifies the AFTR module by relocating the NAPT
NAT function among B4 elements. The lwB4 in Lightweight 4over6 is function among B4 elements located at the subscriber's premises. In
provisioned with an IPv6 address, an IPv4 address and a port-set. It the lw4o6 architecture, the functional elements are referred to as
performs NAPT on end user's packets with the provisioned IPv4 address the lwB4 and lwAFTR.
and port-set. IPv4 packets are forwarded between the lwB4 and the
lwAFTR over a Softwire using IPv4-in-IPv6 encapsulation. The lwAFTR
maintains one mapping entry per subscriber with the IPv6 address,
IPv4 address and port-set. Therefore, this extension removes the
NAT44 module from the AFTR and replaces the session-based NAT table
to a per-subscriber based mapping table. This should relax the
requirement to create dynamic session-based log entries. This
mechanism preserves the dynamic feature of IPv4/IPv6 address binding
as in DS-Lite, so it has no coupling between IPv6 address and IPv4
address/port-set as any full stateless solution ([RFC6052] or
[I-D.ietf-softwire-map]) requires. This document discusses
deployment models of Lightweight 4over6. It also describes the
deployment considerations and applicability of the Lightweight 4over6
architecture.
Terminology of this document follows the definitions and The lwB4 is provisioned with an IPv6 address, a public IPv4 address
abbreviations of [I-D.ietf-softwire-lw4over6]. and a port-set. It performs port-restricted NAPT on subscriber's
packets using the provisioned public IPv4 address and port-set. IPv4
packets are routed between the lwB4 and the lwAFTR encapsulated in an
IPv4 in IPv6 Softwire. The lwAFTR maintains one binding entry per-
subscriber, consisting of the lwB4's IPv6 tunnel endpoint, IPv4
address and port-set. Section 4.4 of [RFC6346] provides more detail
of this mechanism.
2. Deployment Model This can bring a number of advantages when compared to DS-Lite:
o Per-subscriber configuration allows for the operator to provision
each subscriber according to their specific service requirements.
o The logging requirements to meet regulatory requirements may be
reduced as it is only necessary to log when a subscriber is
provisioned or de-provisioned in the lwAFTR. This relaxes the
need for logging on a per-session, or per port block allocation.
o In some lw4o6 deployment topologies, the removal of per-session
state means that it is possible to have very large parallelisation
of lwAFTR elements. This offers excellent scaling and resilience.
o This mechanism preserves the dynamic feature of IPv4/IPv6 address
binding as in DS-Lite, so it has no coupling between IPv6 address
and IPv4 address/port-set as any full stateless solution
([RFC6052] or [RFC7597]) requires.
The terminology used in this document follows the definitions and
abbreviations from [RFC6333] and [RFC7596].
2. Deployment Models
Lightweight 4over6 is suitable for operators who would like to free Lightweight 4over6 is suitable for operators who would like to free
any correlation of the IPv6 address with IPv4 address and port-set any correlation of the IPv6 address with IPv4 address and port-set,
(or port-range). In comparison to full stateless solutions like MAP as the IPv4 addressing is an overlay to the IPv6 addressing
[I-D.ietf-softwire-map] and 4rd [I-D.ietf-softwire-4rd], Lightweight architecture. Thus, IPv6 addressing is completely flexible to fit
4over6 frees address planning of IPv6 delegation for CPE from mapping other deployment requirements, e.g., auto-configuration, service
rule administration and management in the network. Thus, IPv6 classification, user management, QoS support, etc.
addressing is completely flexible to fit other deployment
requirements, e.g., auto-configuration, service classification, user
management, QoS support, etc. The philosophy here is that bits of
IPv6 address should be left for IPv6 usage first.
Lightweight 4over6 can be deployed in a residential network (depicted Lightweight 4over6 can be deployed in a residential ISP network
in Figure1). In this scenario, a lwB4 would acquire an IPv4 address (depicted in Figure 1). In this scenario, a lwB4 acquires an IPv4
and a port-set after a successful user authentication process and address and a port-set alongside IPv6 provisioning, including an
IPv6 provisioning process. Then, it establishes an IPv4-in-IPv6 address for the lwAFTR. It then establishes an IPv4-in-IPv6 softwire
softwire using the IPv6 address to deliver IPv4 services to its to the lwAFTR. The lwB4 function may be implemented in a CPE
connected host via the lwAFTR in the network. The lwB4 can act as a providing IPv4 services for a home network, or directly in a host.
CPE, or software located in the host. The lwAFTR supports
Lightweight 4over6 which keeps the mapping between lwB4's IPv6 The lwAFTR holds a table with the bindings between the lwB4's IPv6
address and its allocated IPv4 address + port set. The supporting addresses and their allocated IPv4 addresses + port sets. The
system may keep the binding information as well for logging and user supporting system is used to syncronise the lwB4 and lwAFTR binding
management. information. It may also be used for logging and user management.
+---------------+ +---------------+
| Supporting | | Supporting |
| System | | System |
+-------+-------+ +-------+-------+
| |
+---------------+--------------| +---------------+-------------+
| | | | |
+---------+ +------+---+ +--+--+ | +---------+ +------+---+ |
| Host | | lwB4 | | | | | Host | | lwB4 | _ _ |
| |--| | ======-| BNG | === +---------+ +-----------+ | |--| |=======( ` )=======+----+----+ +-----------+
+---------+ +----------+ +--|--+ | | | IPv4 | +---------+ +----------+ ( ) _ | | | IPv4 |
| lwAFTR |---| Internet | ( IPv6 ) ) | lwAFTR |---| Internet |
+---------+ +------+---+ +--+--+ | | | | +---------+ +------+---+ ( Network ) | | | |
| Host |--| lwB4 | =======| | ====+---------+ +-----------+ | Host |--| lwB4 |====( ( ) ====+---------+ +-----------+
| | | | | BNG | | | | | | `(_, __)
+---------+ +----------+ +--|--+ | +---------+ +----------+
+ | |
+---------------+--------------+
Figure 1 Deployment Model ---------+ +----------+
Figure 1 Architectural Overview
There are two deployment models in practice: one is called bottom-up 2.1. Top-Down Deployment Model
and the other is top-down. In bottom-up model, after port-restricted
IPv4 address is allocated to a given subscriber, the lwAFTR will In the top-down deployment model, the supporting system holds the
report mapping records to the supporting system on creating a binding overall binding table for the network. It uses this to pre-provision
for traffic logging if necessary. Operators may use the local binding table entries for the lwAFTR and also provision
lwB4s with the correct configuration (e.g. using DHCPv6 or PCP).
With this method, one binding table entry can be present on lwAFTRs
and stateless failover can be achieved.
2.2. Bottom-Up Deployment Model
In the bottom-up model, the client is first provisioned with the
relevant paramters necessary for building the softwire. It then
attempts to send traffic to the lwAFTR.
On receipt of lwB4 traffic which does not have an existing binding-
table entry, one is dynamically created. The lwAFTR reports the new
binding entry to the supporting system.
[I-D.ietf-behave-syslog-nat-logging] or [I-D.ietf-behave-syslog-nat-logging] or
[I-D.ietf-behave-ipfix-nat-logging] to report the port set allocated [I-D.ietf-behave-ipfix-nat-logging] may be used for this purpose. In
by lwAFTR. In this way, the lwAFTR can determine the binding by its this way, the lwAFTR can determine the binding by its own and there
own and there is little impact on existing network architecture. In is little impact on existing network architecture.
top-down model, the Supporting system should firstly determine the
binding information for each subscriber and then synchronize it with 2.3. Campus Deployment
the lwAFTR. With this method, one binding record can be easily
synchronized with multiple lwAFTRs and stateless failover can be
achieved. However, new mechanism (e.g.
[I-D.zhou-dime-4over6-provisioning]) needs to be introduced to notify
each individual binding record between the Supporting system and the
lwAFTR.
Lightweight 4over6 can also be deployed in a campus or enterprise Lightweight 4over6 can also be deployed in a campus or enterprise
network, (depicted in Figure2). In this scenario, a lwB4 acts as a network, (depicted in Figure 2). In this scenario, a lwB4 acts as a
wireless AP and is connected to a number of hosts. The lwB4 first gateway router for a number of hosts. The lwB4 is first provisioned
acquire the IPv4 address and port-set information, then it with an IPv4 address and port-set. It then establishes an IPv4-in-
establishes an IPv4-in-IPv6 softwire using the IPv6 address to IPv6 softwire using the IPv6 address to deliver IPv4 services to its
deliver IPv4 services to its connected host via the lwAFTR in the connected host via the lwAFTR in the network. A network management
network. A network management system could be used to receive system could be used to receive statistic information of the network
statistic information of the network equipments, such as the binding equipments, such as the binding table, network load, and connected
table, network load, and connected device. NETCONF[RFC6241] could be device. NETCONF [RFC6241] could be used for syncronising lwB4's IPv6
used for syncronising lwB4's IPv6 address and its allocated IPv4 address and its allocated IPv4 address + port set with the lwAFTR.
address + port set with the lwAFTR. The network management system The network management system may keep the binding information as
may keep the binding information as well for logging and user well for logging and user management.
management.
+-------------------+ 3. Overall Deployment Considerations
| Network Management|
| System |
+---------+---------+
|
+---------------+--------------|
| |
+---------+ | |
| Host | | |
| |--+ +----------+ +---------+ +-----------+
+---------+ | | | | | | IPv4 |
+ - + lwB4 | ============== | lwAFTR |---| Internet |
+---------+ | | | | | | |
| Host |--+ +----------+ +---------+ +-----------+
| |
+---------+
Figure 2 Deployment Model 3.1. IP Addressing and Routing
3. Overall Deployment Considerations In Lightweight 4over6, there is no inter-dependency between the IPv4
and IPv6 addressing schemes. This allows for complete flexibilty in
addressing architecture.
3.1. Addressing and Routing 3.1.1. IPv4 Routing
In Lightweight 4over6, there is no inter-dependency between IPv4 and The IPv4 addresses/prefixes that are allocated to customer's lwB4s
IPv6 addressing schemes. IPv4 address pools are configured are advertised to the IPv4 Internet as being reachable via the
centralized in lwAFTR for IPv6 subscribers. These IPv4 prefix must lwAFTR(s). If multiple lwAFTRs are all serving the same set of
advertise to IPv4 Internet accordingly. lwB4s, all will advertise the same IPv4 reachable routes.
For IPv6 addressing and routing, there are no additional addressing 3.1.2. IPv6 Routing
and routing requirements. The existing IPv6 address assignment and
routing announcement should not be affected. For example, in PPPoE
scenario, a CPE could obtain a prefix via prefix delegation
procedure, and the hosts behind CPE would get its own IPv6 addresses
within the prefix through SLAAC or DHCPv6 statefully. This IPv6
address assignment procedure has nothing to do with restricted IPv4
address allocation.
3.2. Port-set Management The lwAFTR provides a /128 IPv6 tunnel endpoint address which is
advertsed to the lwB4s. If multiple lwAFTRs are all serving the same
set of lwB4s, all will advertise the same IPv6 tunnel endpoing
address.
In Lightweight 4over6, each lwB4 will get its restricted IPv4 address The lwB4's IPv6 addressing and routing, there are no specific
and a port-set after successful user authentication process and IPv6 topological limitations. An existing IPv6 address and routing
provisioning process. This port-set assignment can been achieved by architecture should not be affected. For example, in PPPoE scenario,
DHCPv4-over-DHCPv6 [I-D.ietf-dhc-dhcpv4-over-dhcpv6] and PCP a CPE could obtain a prefix via DHCPv6 prefix delegation, and the
[I-D.ietf-pcp-port-set]. hosts behind CPE would get its own IPv6 addresses within the prefix
through SLAAC or DHCPv6 statefully. This IPv6 address assignment
procedure has nothing to do with restricted IPv4 address allocation.
Operator may use DHCPv4 to provision IPv4 address to the lwB4. In a It is worth noting that if the Top-Down provisioning model is chosen,
typical deployment, the DHCP server is a centralized DHCP server and then there must be determinism in the local address that the lwB4
lwAFTR is the DHCP relay agent to relay the dhcp messages to the uses for building its tunnel. This is so that the binding entry for
the lwB4 can be pre-provisioned in the lwAFTR. [RFC7598] offers a
solution for this using the 'bind-ipv6-prefix' field is used to
inform the lwB4 which configured prefix to use. The suffix is then
created according to Section 6 of [RFC7597].
3.2. lwB4 Configuration
In lw4o6, each lwB4 will get its restricted IPv4 address and a port-
set after successful user authentication process and IPv6
provisioning process. This assignment can been achieved using a
number of methods:
o DHCPv6 Softwire S46 Option [RFC7598]
o DHCPv4 over DHCPv6 [RFC7341], [RFC7618] and
[I-D.ietf-dhc-dhcp4o6-saddr-opt]
o PCP [RFC7753]
o NETCONF/YANG [I-D.ietf-softwire-yang]
3.2.1. DHCPv6 Based Provisioning
[RFC7598] describes a set of DHCPv6 options used for provisioning
lw4o6 clients. OPTION_S46_CONT_LW (96) is a DHCPv6 contatiner
option, which can hold the IPv6 of the lwAFTR (OPTION_S46_BR (90)),
the lwB4's IPv4 address and IPv6 prefix hint (OPTION_S46_V4V6BIND
(92)), and port set information (OPTION_S46_PORTPARAMS (93)).
In this model, the DHCPv6 server needs to be pre-provisioned with the
client configuration. Therefore, this approach is better suited to
client configurations that will be long-lived.
DHCPv6 based provisioning can also be used in conjunction with a AAA
server. [I-D.ietf-softwire-map-radius] decribes this function.
3.2.2. DHCPv4 over DHCPv6 Based Provisioning
An operator may use DHCPv4 to provision IPv4 address to the lwB4. In
a typical deployment, the DHCP server is a centralized DHCP server
and lwAFTR is the DHCP relay agent to relay the dhcp messages to the
server over unicast. Rarely DHCP server will collocate with the server over unicast. Rarely DHCP server will collocate with the
lwAFTR to provision IPv4 resources to the lwB4. lwAFTR to provision IPv4 resources to the lwB4.
3.2.3. PCP Based Provisioning
Operator may also use PCP Port-set Option to provision IPv4 address Operator may also use PCP Port-set Option to provision IPv4 address
and port-set to the lwB4. In a typical deployment, PCP server will and port-set to the lwB4. In a typical deployment, PCP server will
collocate with lwAFTR, and the subscriber's binding can be determined collocate with lwAFTR, and the subscriber's binding can be determined
by lwAFTR. The PCP request should be sent to the lwAFTR's tunnel by lwAFTR. The PCP request should be sent to the lwAFTR's tunnel
end-point address. It is not common that PCP server will be end-point address. It is not common that PCP server will be
centralized deployed in which the lwAFTR is the PCP proxy to relay centralized deployed in which the lwAFTR is the PCP proxy to relay
PCP requests. PCP requests.
It is also possible that subscriber's binding is determined in AAA 3.2.4. NETCONF/YANG Based Provisioning
server. In this case, the BNGs will embed with a DHCPv4-over-DHCPv6
server function which allows them to locally handle any DHCPv4-over- Operators using NETCONF to manage customer devices can provision
DHCPv6 requests initiated by hosts. The AAA server will pass the lw4o6 using [I-D.ietf-softwire-yang].
subscriber's binding to a BNG using the AAA attribute in [I-D.sun-
softwire-lw4over6-radext] and in turn populates the mapping of the 3.2.5. Other lwB4 Configuation Considerations
lwB4.
Some operators may offer different service level agreements (SLA) to Some operators may offer different service level agreements (SLA) to
users that some users may require more ports then others. In this users that some users may require more ports then others. In this
deployment scenario, the operator can implement differentiated deployment scenario, the operator can implement differentiated
policies in provisioning system specified to a user's lwB4 or a group policies in provisioning system specified to a user's lwB4 or a group
of lwB4s to allocate a certain range of port-set. The lwAFTR may of lwB4s to allocate a certain range of port-set. The lwAFTR may
also run multiple instances with different port-set sizes to build also run multiple instances with different port-set sizes to build
the mapping table. the mapping table.
It is also worth noting the compatibility between lw4o6 and Public
IPv4 over IPv6 [RFC7040]. When a lw4o6 client is provisioned with a
'full' IPv4 address (i.e. with no port-set or a port-set that allows
the use of all of the L4 ports), then the A+P routing model is no
longer used by the lwAFTR as traffic is routed on the IPv4 address
only. This function can be useful when a subscriber usses protocols
which do not have L4 ports.
3.3. lwAFTR Discovery 3.3. lwAFTR Discovery
A Lightweight 4over6 lwB4 must discover the lwAFTR's IPv6 address The lwB4 needs to discover the lwAFTR's IPv6 address before it is
before offering any IPv4 services. This IPv6 address can be learned able to set up the softwire tunnel and provide any IPv4 services.
through an out-of-band channel, static configuration, or dynamic This address can be learned through an out-of-band channel, static
configuration. In practice, Lightweight 4over6 lwB4 can use the same configuration, or dynamic configuration. In practice, Lightweight
DHCPv6 option [RFC6334]to discover the FQDN of the lwAFTR. 4over6 lwB4 can use the same DHCPv6 option [RFC6334] to discover the
FQDN of the lwAFTR.
When Lightweight 4over6 is deployed in the same place with DS-Lite, When Lightweight 4over6 is deployed in the same place with DS-Lite,
either different FQDNs can be configured for Lightweight 4over6 and either different FQDNs can be configured for Lightweight 4over6 and
DS-Lite separately or different DHCPv6 options can be used for DS-Lite separately or different DHCPv6 options can be used for
Lightweight 4over6 [I-D.sun-softwire-lw4over6-dhcpv6] and DS-Lite. Lightweight 4over6 [RFC7598] and DS-Lite. More detailed
More detailed considerations on DS-Lite compatibility will be considerations on DS-Lite compatibility will be discussed in
discussed in Section6. Section 6.
The lw4o6 DHCPv6 option (OPTION_S46_LW_CONT (96)) can contain
OPTION_S46_BR (90) which holds the v6 address of the lwAFTR.
3.4. Impacts on Accouting 3.4. Impacts on Accouting
In Lightweight 4over6, the accounting impact due to the tunneling In lw4o6, the accounting impact due to the tunneling protocol is the
protocol is the same with DS-Lite (see section 6.2 of [RFC6908]). same with DS-Lite (see section 6.2 of [RFC6908]). However, since in
However, since in Lightweight 4over6, the IPv4 service is only lw4o6, the IPv4 service is only available after port-set allocation,
available after port-set allocation, if operators will regard IPv4 if operators regard IPv4 service as a on-demand value-added service,
service as a on-demand value-added service, e.g. IPv6 connectivity e.g. IPv6 connectivity is offered by default, while IPv4
is offered by default, while IPv4 connectivity will be offered untill connectivity will be offered untill a subscriber requires, etc., IPv4
a subscriber requires, etc., IPv4 service accounting should start service accounting should start after port-set allocation has
after port-set allocation has completely. completed.
4. lwAFTR Deployment Consideration It should be noted that in common with all A+P mechanisms, lw4o6 can
not performing per-session logging in the way that CGN based
solutions do.
4. lwAFTR Deployment Considerations
As Lightweight 4over6 is an extension to DS-Lite, both technologies As Lightweight 4over6 is an extension to DS-Lite, both technologies
share similar deployment considerations. For example: Interface share similar deployment considerations. For example: the interface
consideration, Lawful Intercept Considerations, Blacklisting a shared considerations, lawful intercept considerations, blacklisting a
IPv4 Address, AFTR's Policies, AFTR Impacts on Accounting Process, shared IPv4 Address, AFTR policies, and impacts on accounting
etc., in [RFC6908] can also be applied here. This document only processes described in [RFC6908] are also applicable here. This
discusses new considerations specific to Lightweight 4over6. document only discusses addtional considerations specific to
Lightweight 4over6.
4.1. Logging at the lwAFTR 4.1. Logging at the lwAFTR
In Lightweight 4over6, operators only log one entry per subscriber. In lw4o6, operators only log one entry per subscriber. Each log
The log should include subscriber's IPv6 address used for the needs to include subscriber's IPv6 address used for the softwire, the
softwire, the public IPv4 address and the port-set. The port set public IPv4 address and the allocated port-set, and the start and end
algorithm implemented in Lightweight 4over6 lwAFTR should be times that the binding entry was valid for.
synchronized with the one implemented in logging system. For
example, if contiguous port set algorithm is adopted in the lwAFTR,
the same algorithm should also been applied to the logging system.
Since the mapping in lwAFTR does not contain destination-specific To ensure consistency of the logged information, the port set
information, operator should be aware that they will not be able to algorithm implemented in lw4o6 lwAFTR needs to be synchronized with
have destination-specific log. the one implemented in the logging system. For example, if
contiguous port-set algorithm is adopted in the lwAFTR, the same
algorithm needs to be applied for the logging system.
Since the binding in lwAFTR does not log sessions as they are set up,
operators should be aware that lw4o6 does not provided a mechanism
for destination-specific logging.
4.2. MTU and Fragmentation Considerations 4.2. MTU and Fragmentation Considerations
As Lightweight 4over6 is also a tunneling protocol, the same As Lightweight 4over6 uses a tunneling protocol, the same
consideration regarding to the fragmentation and reassembly in DS- considerations regarding fragmentation and reassembly as for DS-Lite
Lite [RFC6908] can also be applied. The only difference is that NAT [RFC6908] are applicable. In order to avoid the problems that are
functionality has been removed to lwB4 from lwAFTR in Lightweight associated with fragmentation, it is advisable to ensure that the MTU
4over6. Therefore, on receiving an IPv4 fragmented packet after across the IPv6 domain between the lwB4 and lwAFTR is large enough to
decapsulation in the lwB4, the lwB4 should further re-assemble the allow for the transportation of IPv4 packets plus the 40-byte
packets before doing NAT since the transport protocol information is overhead for IPv6 encapsulation.
only available in the first fragment.
4.3. Reliability Considerations of lwAFTR 4.3. Reliability Considerations of lwAFTR
Operators may deploy multiple lwAFTRs for robustness, reliability, Operators may deploy multiple lwAFTRs for robustness, reliability,
and load balancing. In Lightweight 4over6, subscriber to IPv4 and and load balancing. In lw4o6, subscriber to IPv4 and port-set
port-set mapping must be pre-provisioned in the lwAFTR before mapping needs to be pre-provisioned in the lwAFTR before an IPv4
providing IPv4 serives. For redundancy, the backup lwAFTR must service can be provided.
either have the subscriber mapping already provisioned or notify the
lwB4 to create a new mapping in the backup lwAFTR. The first option
can be considered as Hot Standby mode, which requires state
syncronization between multiple lwAFTRs. In Hot Standby mode, the
bindings are replicated on-the-fly from the Primary lwAFTR to the
Backup lwAFTR. When the Primary lwAFTR fails, the Backup lwAFTR will
take over all the existing established sessions. In this mode, the
internal hosts are not required to re-initiate the bindings with the
external hosts. In Lightweight 4over6, since the number of mapping
states has been greatly reduced compared to DS-Lite, it is reasonable
to adopt Hot Standby mode when there are only two lwAFTRs (one for
Primary lwAFTR and one for Backup lwAFTR). However, if the number of
lwAFTRs is larger than two, it is not scalable to deploy Hot Standby
mode since each two of the lwAFTRs should to syncronize the binding
states.
The second option is to use Cold Standby mode which does not require For redundancy, one or more backup lwAFTR can have the subscriber
a Backup Standby lwAFTR to synchronize binding states. In failover, bindings already provisioned, e.g. as part of the top-down
the lwAFTR has to notify the lwB4 to create a new binding, or fetch provisioning process described above. In this case, the provisioning
the binding by itself. [I-D.lee-softwire-lw4over6-failover] system is responsible for ensuring that the binding tables of the
describes these two approaches for simple Cold Standby mode. For lwAFTRS are consistent. In this case, as customer traffic arriving
most deployment scenarios, we believe that Cold Standby mode should or returning through either of the lwAFTRs will be processed in the
be sufficient enough and is thus recommended. same way, an active/active redundancy model is possbile.
4.4. Placement of AFTR A second option, which could be more suitable for bottom-up
provisioning, is for the bindings to be replicated between the
primary lwAFTR and the backup lwAFTR. When the primary lwAFTR fails,
the backup lwAFTR has the necessary binding table entries to
correctly forward subscriber traffic. In this mode, the internal
hosts are not required to re-initiate the bindings with the external
hosts. In lw4o6, as the number of binding states have been greatly
reduced compared to DS-Lite, it is reasonable to adopt Hot Standby
mode when there are only two lwAFTRs (a primary and a backup lwAFTR).
However, if the number of lwAFTRs is larger than two, it is not
scalable to deploy using hot standby mode since each two of the
lwAFTRs should to syncronize the binding states.
The lwAFTR can be deployed in a "centralized model" or a "distributed 4.4. Location of lwAFTRs in the Network
model".
In the "centralized model", the lwAFTR could be located at the higher lwAFTR(s) can be deployed in a centralized or a distributed manner.
place, e.g. at the exit of MAN, etc. Since the lwAFTR has good
scalability and can handle numerous concurrent sessions, we recommend
to adopt the "centralized model" for Lightweight 4over6 as it is
cost-effective and easy to manage.
In the "distributed model", lwAFTR is usually integrated with the For a centralized deployment, the lwAFTR(s) are locacate in central
aggregation points in the network, such as a core site, the exit
point from a MAN etc. As the lwAFTR provides the gateway between the
IPv6 and IPv4 networks, it allows single stack IPv6 to be deployed in
the access part of the network.
In a distributed deployment, lwAFTR function is integrated with the
BRAS/SR. Since newly emerging customers might be distributed in the BRAS/SR. Since newly emerging customers might be distributed in the
whole Metro area, we have to deploy lwAFTR on all BRAS/SRs. This whole Metro area, we have to deploy lwAFTR on all BRAS/SRs. This
will cost a lot in the initial phase of the IPv6 transition period. will cost a lot in the initial phase of the IPv6 transition period.
This model also has the drawback of requiring both IPv4 and IPv6 to
the BRAS/Service Router devices and so is unsuitable for providers
wishing to build a single stack IPv6 only core.
4.5. Port set algorithm consideration 4.5. Path Consistency Consideration
If each lwB4 is given a set of ports, port randomization algorithm In Lightweight 4over6, if the binding state is not syncronized among
can only select port in the given port-set. This may introduce multiple lwAFTRs, the lwAFTR in which the subscriber's binding state
security risk because hackers can make a more predictable guess of is stored should be exactly the one to service the subscriber.
what port a subscriber may use. Therefore, non-continuous port set Otherwise, there will be no match in the lwAFTR. This can be
algorithms (e.g. as defined in [I-D.ietf-softwire-map]) can be used achieved by using a unique IPv6 tunnel endpoint address and
to improve security. corresponding reachable public IPv4 customer prefix for each lwAFTR.
4.6. Path Consistency Consideration If multiple lwAFTRs are deployed for resilience or scalability, using
the top-down provisioning model, all of the lwAFTRs in this cluster
will share the same IPv6 tunnel endpoint and set of reachable
prefixes. In this case, any packet arriving at any of the cluster
members will be processed in the same way. However, it is worth
considering using ECMP with flow-hashing so that a single customer's
traffic will be processed by the same lwAFTR. This will reduce the
change of packet re-ordering.
In Lightweight 4over6, if the binding state is not syncronized among In Lightweight 4over6, if the binding state is not syncronized among
multiple lwAFTRs, the lwAFTR in which the subscriber's binding state multiple lwAFTRs, the lwAFTR in which the subscriber's binding state
is stored should be exactly the one to service the subscriber. is stored should be exactly the one to service the subscriber.
Otherwise, there will be no match in lwAFTR. This requires the Otherwise, there will be no match in lwAFTR. This requires the
provionsion packets (either using DHCPv4-over-DHCPv6 or PCP Port-set) provionsion packets (either using DHCPv4-over-DHCPv6 or PCP Port-set)
should arrive at the same lwAFTR as the subsquent IP-in-IP traffic. should arrive at the same lwAFTR as the subsquent IP-in-IP traffic.
If multiple lwAFTRs are using the same Tunnel End Point address and If multiple lwAFTRs are using the same Tunnel End Point address and
there are intermediate routers between lwB4 and lwAFTR, there might there are intermediate routers between lwB4 and lwAFTR, there might
be a problem when intermediate routers perform ECMP based on L4 hash be a problem when intermediate routers perform ECMP based on L4 hash
for the plain provionsion packets while doing L3 hash for subsequent for the plain provionsion packets while doing L3 hash for subsequent
IP-in-IP traffic. In this case, it is recommended that the IP-in-IP traffic. In this case, it is recommended that the
privioning packet is sent over IPv6 tunnel so that intermediate provisioning packet is sent over IPv6 tunnel so that intermediate
routers can only process ECMP using L3 hash. routers can only process ECMP using L3 hash.
5. lwB4 Deployment Consideration 5. lwB4 Deployment Considerations
For lwB4 consideration, the DNS Deployment Considerations and B4 For the lwB4, the DNS Deployment Considerations and B4 Remote
Remote Management in [RFC6908] can also be applied here. In this Management in [RFC6908] can also be applied here. In this section,
section, we only describe the considerations sepcific to Lightweight only additional considerations relevant to lw4o6 are discussed.
4over6.
5.1. NAT traversal issue 5.1. NAT Traversal Issues
In Lightweight 4over6, since the subscriber's source port will be In lw4o6, as the subscriber's traffic source port will be restricted
restricted to the port-set allocated from the provisioning system, to the port-set allocated from the provisioning system, there will be
this will have impact on some NAT traversal mechanisms. For example, an impact on some NAT traversal mechanisms. For example, in UPnP
in UPnP 1.0, the external port number which can be used by remote 1.0, the external port number that can be used by a remote peer is
peer is selected by UPnP client in end host. If the client randomly selected by a UPnP client in end host. If the client randomly
selects a port number which is not in that valid port-set, the UPnP selects a port number which dos not fall in that valid port-set, the
process will fail. This is likely to happen because end-host does UPnP process will fail.
not know the port-set in lwB4. More detailed experimental results
can be found in [I-D.deng-aplusp-experiment-results]. This problem This is likely to happen because an end-host does not have knowledge
will not exist in UPnP 2.0 because the UPnP client in the end-host of the port-set which has been allocated to the lwB4. More detailed
will negotiate the external port number with the server. Another way experimental results can be found in
is to implement a mechanism (e.g. [I-D.ietf-pcp-port-set], etc.) in [I-D.deng-aplusp-experiment-results]. This problem will not exist in
end host to fetch the port-set from lwB4. The UPnP client can then UPnP 2.0 because the end-host's UPnP client in the will negotiate the
select the port number within the port-set. external port number with the server. Another way is to implement a
mechanism (e.g. [RFC7753]) in end host to fetch the allocated port-
set from the lwB4. The UPnP client can then select the port number
within the port-set.
5.2. Static Port Forwarding Configuration 5.2. Static Port Forwarding Configuration
Currently, some external initiated applications rely on manual port Currently, some externally initiated applications rely on manual
configuration to reserve a port in the CPE. The restricted port-set configuration to reserve a port in the CPE. The restricted port-set
in lwB4 will also have impacts on manual port forwarding used by the lwB4 may be problematic for manual port forwarding
configuration. It is recommended that the port-set allocated from configuration. It is recommended that the port-set allocated from
the provioning system should be shown explicitly in the lwB4, which the provioning system should be visible to the user (e.g. via the
can be used as a hint for subscribers to add port forwarding mapping. configuration interface of a HGW which implements the lwB4 function),
which can be used as a hint for subscribers to add port forwarding
mapping.
It should also be noted that the well-known ports are not generally
allocated to a lwB4, unless the client is being allocated a full IPv4
address with no address sharing ([RFC7596], Section 5.1). If the
user wishes to make a service running on an end-host using a well-
known port externally accessible, it is necessary to configure the
lwB4's port-forwarding to re-map the well-known port to a port taken
from the allocated port-set.
6. DS-Lite Compatibility Consideration 6. DS-Lite Compatibility Consideration
Lightweight 4over6 can be either deployed all alone, or combined with Lightweight 4over6 can be either deployed as a complete solution, or
DS-Lite [RFC6333]. Since Lightweight 4over6 does not any have extra in conjuction with DS-Lite. Since Lightweight 4over6 does not any
requirement on IPv6 addressing, it can use use the same addressing have extra requirement on IPv6 addressing, it can use use the same
scheme with DS-Lite, together with routing policy, user management addressing scheme with DS-Lite, together with routing policy, user
policy, etc. Besides, the bottom-up model has quite similar management policy, etc. Besides, the bottom-up model has quite
requirement and workflow on the supporting system with DS-Lite. similar requirement and workflow on the supporting system with DS-
Therefore, it is suitable for operators to deploy incrementally in Lite. Therefore, it is suitable for operators to deploy
existing DS-Lite network incrementally in existing DS-Lite network
6.1. Case 1: Integrated Network Element with Lightweight 4over6 and DS- 6.1. Case 1: Integrated Network Element with Lightweight 4over6 and DS-
Lite AFTR Scenario Lite AFTR Scenario
In this case, DS-Lite has been deployed in the network. Later in the In this case, DS-Lite has been deployed in the network. Later in the
deployment schedule, the operator decided to implement Lightweight deployment schedule, the operator decided to implement Lightweight
4over6 lwAFTR function in the same network element(depicted in 4over6 lwAFTR function in the same network element (depicted in
Figure3). Therefore, the same network element needs to support both Figure3, below). Therefore, the same network element needs to
transition mechanisms. support both transition mechanisms.
There are two options to distinguish the traffic from two transition There are two options to distinguish the traffic from two transition
mechanisms. mechanisms.
The first one is to distinguish using the client's source IPv4 The first one is to distinguish using the client's source IPv4
address. The IPv4 address from Lightweight 4over6 is public address address. The IPv4 address from Lightweight 4over6 is public address
as NAT has been done in the lwB4, and IPv4 address for DS-lite is as NAT has been done in the lwB4, and IPv4 address for DS-lite is
private address as NAT will be done on AFTR. When the network private address as NAT will be done on AFTR. When the network
element receives an encapsulated packet, it would de-capsulate packet element receives an encapsulated packet, it would de-capsulate packet
and apply the transition mechanism based on the IPv4 source address and apply the transition mechanism based on the IPv4 source address
skipping to change at page 12, line 47 skipping to change at page 13, line 4
can use the same DHCPv6 option [RFC6334] with the same FQDN of the can use the same DHCPv6 option [RFC6334] with the same FQDN of the
AFTR and lwAFTR. AFTR and lwAFTR.
The second one is to distinguish using the destination's tunnel IPv6 The second one is to distinguish using the destination's tunnel IPv6
address. One network element can run separated instances for address. One network element can run separated instances for
Lightweight 4over6 and DS-Lite with different tunnel addresses. Then Lightweight 4over6 and DS-Lite with different tunnel addresses. Then
B4 element and Lightweight 4over6 lwB4 can use the same DHCPv6 option B4 element and Lightweight 4over6 lwB4 can use the same DHCPv6 option
[RFC6334] with different FQDNs pointing to corresponding tunnel [RFC6334] with different FQDNs pointing to corresponding tunnel
addresses. This requires the supporting system should distinguish addresses. This requires the supporting system should distinguish
different types of users when assigning the FQDNs in DHCPv6 process. different types of users when assigning the FQDNs in DHCPv6 process.
Another option is to use a new DHCPv6 option
[I-D.sun-softwire-lw4over6-dhcpv6] to discover lwAFTR's FQDN. Another option is to use a new DHCPv6 option [RFC7598] to discover
the lwAFTR's FQDN.
+---------------+--------------| +---------------+--------------|
+ | | + | |
+---------+ +------+---+ +--+--+ | +---------+ +------+---+ +--+--+ |
| Host | | LW 4over6| | | | | Host | | LW 4over6| | | |
| |--| lwB4 | ======-| BNG | === +-------------+ +-----------+ | |--| lwB4 | ======-| BNG | === +-------------+ +-----------+
+---------+ +----------+ +--|--+ |LW 4over6 | | IPv4 | +---------+ +----------+ +--|--+ |LW 4over6 | | IPv4 |
|lwAFTR/ |---| Internet | |lwAFTR/ |---| Internet |
+---------+ +------+---+ +--+--+ |DS-Lite AFTR | | | +---------+ +------+---+ +--+--+ |DS-Lite AFTR | | |
| Host |--| DS-Lite | =======| | ====+-------------+ +-----------+ | Host |--| DS-Lite | =======| | ====+-------------+ +-----------+
| | | B4 | | BNG | | | | | B4 | | BNG | |
+---------+ +----------+ +--|--+ | +---------+ +----------+ +--|--+ |
+ | | + | |
+---------------+--------------+ +---------------+--------------+
Figure 3 DS-Lite Coexistence scenario with Integrated AFTR Figure 3 DS-Lite Coexistence scenario with Integrated AFTR
6.2. Case 2: DS-Lite Coexistent scenario with Separated AFTR 6.2. Case 2: DS-Lite Coexistent scenario with Separated AFTR
This is similar to Case 1. The difference is the lwAFTR and AFTR This is similar to Case 1. The difference is the lwAFTR and AFTR
functions won't be co-located in the same network element (depicted functions won't be co-located in the same network element (depicted
in Figure4). This use case decouples the functions to allow more in Figure4). This use case decouples the functions to allow more
flexible deployment. For example, an operator may deploy AFTR closer flexible deployment. For example, an operator may deploy AFTR closer
to the edge and lwAFTR closer to the core. Moreover, it does not to the edge and lwAFTR closer to the core. Moreover, it does not
require the network element to pre-configure with the CPE's IPv6 require the network element to pre-configure with the CPE's IPv6
addresses. An operator can deploy more AFTR and lwAFTR at needed. addresses. An operator can deploy more AFTR and lwAFTR at needed.
However, this requires the B4 and lwB4 to discover the corresponding However, this requires the B4 and lwB4 to discover the corresponding
network element. In this case, B4 element and Lightweight 4over6 network element. In this case, B4 element and Lightweight 4over6
lwB4 can still use [RFC6334] with different FQDNs pointing to lwB4 can still use [RFC6334] with different FQDNs pointing to
corresponding tunnel end-point addresses, and the supporting system corresponding tunnel end-point addresses, and the supporting system
should distinguish different types of users. should distinguish different types of users.
+---+---------------+-----------------| +------------------+-----------------|
+ | | | | |
+---------+ +------+---+ +------+-----+ | +---------+ +------+---+ +------+-----+ |
| Host | | LW 4over6| | BNG | | | Host |__| LW 4over6| | BNG | |
| |--| lwB4 | ======-|DS-Lite AFTR| === +------------+ +-----------+ | | | lwB4 |=======|DS-Lite AFTR|=====+------------+ +----------+
+---------+ +----------+ +------+-----+ | LW 4over6 | | IPv4 | +---------+ +----------+ +------+-----+ | lw4o6 | | IPv4 |
| lwAFTR |---| Internet | | lwAFTR |---| Internet |
+---------+ +------+---+ +------+-----+ | | | | +---------+ +------+---+ +------+-----+ | | | |
| Host |--| DS-Lite | =======| BNG | ====+------------+ +-----------+ | Host |__| DS-Lite |=======| BNG |=====+------------+ +----------+
| | | B4 | |DS-Lite AFTR| | | | | B4 | |DS-Lite AFTR| |
+---------+ +----------+ +------+-----+ | +---------+ +----------+ +------+-----+ |
+ | | | | |
+-------------------+-----------------+ +------------------+-----------------+
Figure 4 DS-Lite Coexistence scenario with Seperated AFTR Figure 4 DS-Lite Co-existence scenario with Seperated AFTR/lwAFTR
7. Acknowledgement 7. Acknowledgements
TBD TBD
8. References 8. References
[I-D.bajko-pripaddrassign] [I-D.bajko-pripaddrassign]
Bajko, G., Savolainen, T., Boucadair, M., and P. Levis, Bajko, G., Savolainen, T., Boucadair, M., and P. Levis,
"Port Restricted IP Address Assignment", "Port Restricted IP Address Assignment", draft-bajko-
draft-bajko-pripaddrassign-04 (work in progress), pripaddrassign-04 (work in progress), April 2012.
April 2012.
[I-D.cui-softwire-b4-translated-ds-lite] [I-D.cui-softwire-b4-translated-ds-lite]
Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I. Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I.
Farrer, "Lightweight 4over6: An Extension to the DS-Lite Farrer, "Lightweight 4over6: An Extension to the DS-Lite
Architecture", draft-cui-softwire-b4-translated-ds-lite-11 Architecture", draft-cui-softwire-b4-translated-ds-lite-11
(work in progress), February 2013. (work in progress), February 2013.
[I-D.deng-aplusp-experiment-results] [I-D.deng-aplusp-experiment-results]
Deng, X., Boucadair, M., and F. Telecom, "Implementing A+P Deng, X., Boucadair, M., and F. Telecom, "Implementing A+P
in the provider's IPv6-only network", in the provider's IPv6-only network", draft-deng-aplusp-
draft-deng-aplusp-experiment-results-00 (work in experiment-results-00 (work in progress), March 2011.
progress), March 2011.
[I-D.ietf-behave-ipfix-nat-logging] [I-D.ietf-behave-ipfix-nat-logging]
Sivakumar, S. and R. Penno, "IPFIX Information Elements Sivakumar, S. and R. Penno, "IPFIX Information Elements
for logging NAT Events", for logging NAT Events", draft-ietf-behave-ipfix-nat-
draft-ietf-behave-ipfix-nat-logging-13 (work in progress), logging-13 (work in progress), January 2017.
January 2017.
[I-D.ietf-behave-syslog-nat-logging] [I-D.ietf-behave-syslog-nat-logging]
Chen, Z., Zhou, C., Tsou, T., and T. Taylor, "Syslog Chen, Z., Zhou, C., Tsou, T., and T. Taylor, "Syslog
Format for NAT Logging", Format for NAT Logging", draft-ietf-behave-syslog-nat-
draft-ietf-behave-syslog-nat-logging-06 (work in logging-06 (work in progress), January 2014.
progress), January 2014.
[I-D.ietf-dhc-dhcpv4-over-ipv6] [I-D.ietf-dhc-dhcp4o6-saddr-opt]
Cui, Y., Wu, P., Wu, J., Lemon, T., and Q. Sun, "DHCPv4 Farrer, I., Sun, Q., Cui, Y., and L. Sun, "DHCPv4 over
over IPv6 Transport", draft-ietf-dhc-dhcpv4-over-ipv6-09 DHCPv6 Source Address Option", draft-ietf-dhc-dhcp4o6-
(work in progress), April 2014. saddr-opt-00 (work in progress), March 2017.
[I-D.ietf-pcp-base] [I-D.ietf-pcp-base]
Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P. Wing, D., Cheshire, S., Boucadair, M., Penno, R., and P.
Selkirk, "Port Control Protocol (PCP)", Selkirk, "Port Control Protocol (PCP)", draft-ietf-pcp-
draft-ietf-pcp-base-29 (work in progress), November 2012. base-29 (work in progress), November 2012.
[I-D.ietf-pcp-port-set]
Qiong, Q., Boucadair, M., Sivakumar, S., Zhou, C., Tsou,
T., and S. Perreault, "Port Control Protocol (PCP)
Extension for Port Set Allocation",
draft-ietf-pcp-port-set-13 (work in progress),
October 2015.
[I-D.ietf-softwire-4rd]
Despres, R., Jiang, S., Penno, R., Lee, Y., Chen, G., and
M. Chen, "IPv4 Residual Deployment via IPv6 - a Stateless
Solution (4rd)", draft-ietf-softwire-4rd-10 (work in
progress), December 2014.
[I-D.ietf-softwire-dslite-deployment] [I-D.ietf-softwire-dslite-deployment]
Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M. Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M.
Boucadair, "Deployment Considerations for Dual-Stack Boucadair, "Deployment Considerations for Dual-Stack
Lite", draft-ietf-softwire-dslite-deployment-08 (work in Lite", draft-ietf-softwire-dslite-deployment-08 (work in
progress), January 2013. progress), January 2013.
[I-D.ietf-softwire-lw4over6] [I-D.ietf-softwire-map-radius]
Cui, Y., Qiong, Q., Boucadair, M., Tsou, T., Lee, Y., and Jiang, S., Fu, Y., Liu, B., Deacon, P., Xie, C., and T.
I. Farrer, "Lightweight 4over6: An Extension to the DS- Li, "RADIUS Attribute for Softwire Address plus Port based
Lite Architecture", draft-ietf-softwire-lw4over6-13 (work Mechanisms", draft-ietf-softwire-map-radius-12 (work in
in progress), November 2014. progress), May 2017.
[I-D.ietf-softwire-map] [I-D.ietf-softwire-yang]
Troan, O., Dec, W., Li, X., Bao, C., Matsushima, S., Sun, Q., Wang, H., Cui, Y., Farrer, I., Zoric, S.,
Murakami, T., and T. Taylor, "Mapping of Address and Port Boucadair, M., and R. Asati, "A YANG Data Model for IPv4-
with Encapsulation (MAP)", draft-ietf-softwire-map-13 in-IPv6 Softwires", draft-ietf-softwire-yang-01 (work in
(work in progress), March 2015. progress), October 2016.
[I-D.lee-softwire-lw4over6-failover] [I-D.lee-softwire-lw4over6-failover]
Lee, Y., Qiong, Q., and C. Liu, "Simple Failover Mechanism Lee, Y., Qiong, Q., and C. Liu, "Simple Failover Mechanism
for Lightweight 4over6", for Lightweight 4over6", draft-lee-softwire-
draft-lee-softwire-lw4over6-failover-01 (work in lw4over6-failover-01 (work in progress), July 2013.
progress), July 2013.
[I-D.sun-softwire-lw4over6-dhcpv6] [I-D.sun-softwire-lw4over6-dhcpv6]
Xie, C., Qiong, Q., Lee, Y., Tsou, T., and P. Wu, "Dynamic Xie, C., Qiong, Q., Lee, Y., Tsou, T., and P. Wu, "Dynamic
Host Configuration Protocol for IPv6 (DHCPv6) Option for Host Configuration Protocol for IPv6 (DHCPv6) Option for
Lightweight 4over6", draft-sun-softwire-lw4over6-dhcpv6-00 Lightweight 4over6", draft-sun-softwire-lw4over6-dhcpv6-00
(work in progress), July 2013. (work in progress), July 2013.
[I-D.zhou-dime-4over6-provisioning] [I-D.zhou-dime-4over6-provisioning]
Zhou, C., Taylor, T., Qiong, Q., and M. Boucadair, Zhou, C., Taylor, T., Qiong, Q., and M. Boucadair,
"Attribute-Value Pairs For Provisioning Customer Equipment "Attribute-Value Pairs For Provisioning Customer Equipment
Supporting IPv4-Over-IPv6 Transitional Solutions", Supporting IPv4-Over-IPv6 Transitional Solutions", draft-
draft-zhou-dime-4over6-provisioning-05 (work in progress), zhou-dime-4over6-provisioning-05 (work in progress),
September 2014. September 2014.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/ Requirement Levels", BCP 14, RFC 2119,
RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <http://www.rfc-editor.org/info/rfc2119>.
[RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X. [RFC6052] Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052, Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
DOI 10.17487/RFC6052, October 2010, DOI 10.17487/RFC6052, October 2010,
<http://www.rfc-editor.org/info/rfc6052>. <http://www.rfc-editor.org/info/rfc6052>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
skipping to change at page 17, line 25 skipping to change at page 16, line 30
[RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual- [RFC6333] Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
Stack Lite Broadband Deployments Following IPv4 Stack Lite Broadband Deployments Following IPv4
Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011, Exhaustion", RFC 6333, DOI 10.17487/RFC6333, August 2011,
<http://www.rfc-editor.org/info/rfc6333>. <http://www.rfc-editor.org/info/rfc6333>.
[RFC6334] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration [RFC6334] Hankins, D. and T. Mrugalski, "Dynamic Host Configuration
Protocol for IPv6 (DHCPv6) Option for Dual-Stack Lite", Protocol for IPv6 (DHCPv6) Option for Dual-Stack Lite",
RFC 6334, DOI 10.17487/RFC6334, August 2011, RFC 6334, DOI 10.17487/RFC6334, August 2011,
<http://www.rfc-editor.org/info/rfc6334>. <http://www.rfc-editor.org/info/rfc6334>.
[RFC6346] Bush, R., Ed., "The Address plus Port (A+P) Approach to
the IPv4 Address Shortage", RFC 6346,
DOI 10.17487/RFC6346, August 2011,
<http://www.rfc-editor.org/info/rfc6346>.
[RFC6431] Boucadair, M., Levis, P., Bajko, G., Savolainen, T., and [RFC6431] Boucadair, M., Levis, P., Bajko, G., Savolainen, T., and
T. Tsou, "Huawei Port Range Configuration Options for PPP T. Tsou, "Huawei Port Range Configuration Options for PPP
IP Control Protocol (IPCP)", RFC 6431, DOI 10.17487/ IP Control Protocol (IPCP)", RFC 6431,
RFC6431, November 2011, DOI 10.17487/RFC6431, November 2011,
<http://www.rfc-editor.org/info/rfc6431>. <http://www.rfc-editor.org/info/rfc6431>.
[RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M. [RFC6908] Lee, Y., Maglione, R., Williams, C., Jacquenet, C., and M.
Boucadair, "Deployment Considerations for Dual-Stack Boucadair, "Deployment Considerations for Dual-Stack
Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013, Lite", RFC 6908, DOI 10.17487/RFC6908, March 2013,
<http://www.rfc-editor.org/info/rfc6908>. <http://www.rfc-editor.org/info/rfc6908>.
[RFC7040] Cui, Y., Wu, J., Wu, P., Vautrin, O., and Y. Lee, "Public
IPv4-over-IPv6 Access Network", RFC 7040,
DOI 10.17487/RFC7040, November 2013,
<http://www.rfc-editor.org/info/rfc7040>.
[RFC7341] Sun, Q., Cui, Y., Siodelski, M., Krishnan, S., and I. [RFC7341] Sun, Q., Cui, Y., Siodelski, M., Krishnan, S., and I.
Farrer, "DHCPv4-over-DHCPv6 (DHCP 4o6) Transport", Farrer, "DHCPv4-over-DHCPv6 (DHCP 4o6) Transport",
RFC 7341, DOI 10.17487/RFC7341, August 2014, RFC 7341, DOI 10.17487/RFC7341, August 2014,
<http://www.rfc-editor.org/info/rfc7341>. <http://www.rfc-editor.org/info/rfc7341>.
[RFC7596] Cui, Y., Sun, Q., Boucadair, M., Tsou, T., Lee, Y., and I.
Farrer, "Lightweight 4over6: An Extension to the Dual-
Stack Lite Architecture", RFC 7596, DOI 10.17487/RFC7596,
July 2015, <http://www.rfc-editor.org/info/rfc7596>.
[RFC7597] Troan, O., Ed., Dec, W., Li, X., Bao, C., Matsushima, S.,
Murakami, T., and T. Taylor, Ed., "Mapping of Address and
Port with Encapsulation (MAP-E)", RFC 7597,
DOI 10.17487/RFC7597, July 2015,
<http://www.rfc-editor.org/info/rfc7597>.
[RFC7598] Mrugalski, T., Troan, O., Farrer, I., Perreault, S., Dec,
W., Bao, C., Yeh, L., and X. Deng, "DHCPv6 Options for
Configuration of Softwire Address and Port-Mapped
Clients", RFC 7598, DOI 10.17487/RFC7598, July 2015,
<http://www.rfc-editor.org/info/rfc7598>.
[RFC7600] Despres, R., Jiang, S., Ed., Penno, R., Lee, Y., Chen, G.,
and M. Chen, "IPv4 Residual Deployment via IPv6 - A
Stateless Solution (4rd)", RFC 7600, DOI 10.17487/RFC7600,
July 2015, <http://www.rfc-editor.org/info/rfc7600>.
[RFC7618] Cui, Y., Sun, Q., Farrer, I., Lee, Y., Sun, Q., and M. [RFC7618] Cui, Y., Sun, Q., Farrer, I., Lee, Y., Sun, Q., and M.
Boucadair, "Dynamic Allocation of Shared IPv4 Addresses", Boucadair, "Dynamic Allocation of Shared IPv4 Addresses",
RFC 7618, DOI 10.17487/RFC7618, August 2015, RFC 7618, DOI 10.17487/RFC7618, August 2015,
<http://www.rfc-editor.org/info/rfc7618>. <http://www.rfc-editor.org/info/rfc7618>.
1. China Telecom Experimental Result [RFC7753] Sun, Q., Boucadair, M., Sivakumar, S., Zhou, C., Tsou, T.,
and S. Perreault, "Port Control Protocol (PCP) Extension
for Port-Set Allocation", RFC 7753, DOI 10.17487/RFC7753,
February 2016, <http://www.rfc-editor.org/info/rfc7753>.
Appendix A. China Telecom Experimental Results
We have deployed Lightweight 4over6 in our operational network of We have deployed Lightweight 4over6 in our operational network of
HuNan province, China. It is designed for broadband access network, HuNan province, China. It is designed for broadband access network,
and different versions of lwB4 have been implemented including a and different versions of the lwB4 function have been implemented
linksys box, a software client for windows XP, vista and Windows 7. including a Linksys device, a software client for Windows XP, Windows
Vista and Windows 7.
It can be integrated with existing dial-up mechanisms such as PPPoE, It can be integrated with existing dial-up mechanisms such as PPPoE,
etc. The major objectives listed below aimed to verify the etc. The major objectives listed below aimed to verify the
functionality and performance of Lightweight 4over6: functionality and performance of Lightweight 4over6:
o Verify how to deploy Lightweight 4over6 in a practical network. o Verify how to deploy Lightweight 4over6 in a practical network.
o Verify the impact of applications with Lightweight 4over6. o Verify the impact of applications with Lightweight 4over6.
o Verify the performance of Lightweight 4over6. o Verify the performance of Lightweight 4over6.
1.1. Experimental Environment A.1. Experimental Environment
The network topology for this experiment is depicted in Figure 5. The network topology for this experiment is depicted in Figure 5.
+--------+ +--------+
+-----+ +-------+ | Syslog | +-----+ +-------+ | Syslog |
|Host1+--+lwB4 |----+ | Server | |Host1+--+lwB4 |----+ | Server |
+-----+ +-------+ | +---+----+ --------- +-----+ +-------+ | +---+----+ ---------
| /------\ | // \\ | /------\ | // \\
| // \\ | / \ | // \\ | / \
+-----+ +-------+ +-+--+ | IPv6 | +---+----+ | | +-----+ +-------+ +-+--+ | IPv6 | +---+----+ | |
|Host2+--|lwB4 |----+BRAS+--| Network |---|lwAFTR +-+ IPv4 Internet + |Host2+--|lwB4 |----+BRAS+--| Network |---|lwAFTR +-+ IPv4 Internet +
+-----+ +-------+ +-+--+ \\ // +--------+ | | +-----+ +-------+ +-+--+ \\ // +--------+ | |
| \--+---/ (PCP Server) \ / | \--+---/ (PCP Server) \ /
| | \\ // | | \\ //
+-----+ +-------+ | | --------- +-----+ +-------+ | | ---------
|Host3+--+lwB4 +----+ | |Host3+--+lwB4 +----+ |
+-----+ +-------+ | --------- +-----+ +-------+ | ---------
| // \\ | // \\
| / \ | / \
| | | | | |
+--------------------+ IPv6 Internet + +--------------------+ IPv6 Internet +
| | | |
\ / \ /
\\ // \\ //
--------- ---------
Figure 5 China Telecom Lightweight 4over6 experiment topology Figure 5 China Telecom Lightweight 4over6 Experiment Topology
In this deployment model, lwAFTR is co-located with a extended PCP In this deployment model, the lwAFTR is co-located with an extended
server to assign restricted IPv4 address and port set for lwB4. It PCP server to assign port-restricted IPv4 addresses and port-sets to
also triggers subscriber-based logging event to a centrilized syslog lwB4s. It also triggers subscriber-based logging event to a
server. IPv6 address pools for subscribers have been distributed to centrilized syslog server. IPv6 address pools for subscribers have
BRASs for configuration, while the public available IPv4 address been distributed to BRASs for configuration, while the available
pools are configured by the centralized lwAFTR with a default address public IPv4 address pools are configured by the centralized lwAFTR
sharing ratio. It is rather flexible for IPv6 addressing and with a default address sharing ratio. It is rather flexible for IPv6
routing, and there is little impact on existing IPv6 architecture. addressing and routing, and there is little impact on existing IPv6
architecture.
In our experiment, lwB4 will firstly get its IPv6 address and In our experiment, lwB4 will firstly get its IPv6 address and
delegated prefix through PPPoE, and then initiate a PCP-extended delegated prefix through PPPoE, and then initiate a PCP-extended
request to get public IPv4 address and its valid port set. The request to get public IPv4 address and its valid port set. The
lwAFTR will thus create a subscriber-based state accordingly, and lwAFTR will thus create a subscriber-based state accordingly, and
notify syslog server with {IPv6 address, IPv4 address, port set, notify the syslog server with {IPv6 address, IPv4 address, port set,
timestamp}. timestamp}.
1.2. Experimental Results A.2. Experimental Results
In our trial, we mainly focused on application test and performance In our trial, we mainly focused on application and performance tests.
test. The applications have widely include web, email, Instant The applications tested include web (HTTP/HTTPS), email, instant
Message, ftp, telnet, SSH, video, Video Camera, P2P, online game, messaging, FTP, telnet, SSH, video, Video Camera, P2P, online gaming,
voip and so on. For performance test, we have measured the and VoIP.
parameters of concurrent session numbers and throughput performance.
For the performance tests, we measured the number of concurrent
session and throughput performance.
The experimental results are listed as follows: The experimental results are listed as follows:
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| Application Type | Test Result |Port Number Occupation | | Application Type | Test Result |Port Number Occupation |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| Web | ok | normal websites: 10~20| | Web | OK | normal websites: 10~20|
| | IE, Firefox, Chrome | Ajex Flash webs: 30~40| | | IE, Firefox, Chrome | Ajex Flash webs: 30~40|
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| Video | ok, web based or | 30~40 | | Video | ok, web based or | 30~40 |
| | client based | | | | client based | |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| Instant Message | ok | | | Instant Message | OK | |
| | QQ, MSN, gtalk, skype| 8~20 | | | QQ, MSN, gtalk, skype| 8~20 |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| P2P | ok | lower speed: 20~600 | | P2P | OK | lower speed: 20~600 |
| |utorrent,emule,xunlei | (per seed) | | |utorrent,emule,xunlei | (per seed) |
| | | higher speed: 150~300 | | | | higher speed: 150~300 |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| FTP | need ALG for active | 2 | | FTP | need ALG for active | 2 |
| | mode, flashxp | | | | mode, flashxp | |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| SSH, TELNET | ok |1 for SSH, 3 for telnet| | SSH, TELNET | OK |1 for SSH, 3 for telnet|
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
| online game | ok for QQ, flash game| 20~40 | | online game | OK for QQ, flash game| 20~40 |
+--------------------+----------------------+-----------------------+ +--------------------+----------------------+-----------------------+
Figure 6 China Telecom 4over6 experimental result Figure 6 China Telecom Lightweight 4over6 Experiment Results
The performance test for lwAFTR is taken on a normal PC. Due to
The performance tests for the lwAFTR are taken using a PC. Due to
limitations of the PC hardware, the overall throughput is limited to limitations of the PC hardware, the overall throughput is limited to
around 800 Mbps. However, it can still support more than one hundred around 800 Mbps. However, it can still support more than one hundred
million concurrent sessions. million concurrent sessions.
1.3. Conclusions A.3. Conclusions
From the experiment, we can have the following conclusions: From the experiment, we reached the following conclusions:
o Lightweight 4over6 has good scalability. As it is a lightweight o Lightweight 4over6 has good scalability. As it is a lightweight
solution which only maintains per-subscription state information, solution that only maintains per-subscription state information,
it can easily support a large amount of concurrent subscribers. it can easily support a large amount of concurrent subscribers.
o Lightweight 4over6 can be deployed rapidly. There is no o Lightweight 4over6 can be deployed rapidly. No modifications to
modification to existing addressing and routing system in our the existing addressing and routing system in our operational
operational network. And it is simple to achieve traffic logging. network was necessary. Logging of customer address allocations
was easy to implement.
o Lightweight 4over6 can support a majority of current IPv4 o Lightweight 4over6 can support the majority of current IPv4
applications. applications commonly in use.
2. Tsinghua University Experimental Result Appendix B. Tsinghua University Experimental Result
Lightweight 4over6 has also been deployed in the campus of Tsinghua Lightweight 4over6 has been deployed in the campus of Tsinghua
University, China. We use DHCPv4 over DHCPv6 [RFC7341] for the University, China. DHCPv4o6 [RFC7341] is used for dynamically
dynamic provisioning of lwB4's IPv4 address and port set [RFC7618]. provisioning the lwB4's IPv4 address and port set [RFC7618].
We deployed wireless APs for Lightweight 4over6, covering a large Wireless APs for Lightweight 4over6, were deployed, covering a large
portion of the campus, allowing mobile devices to connect to the portion of the campus, allowing mobile devices to connect to the
lwB4. We also deployed lwB4 gateway in some of our buildings so PCs lwB4. We also deployed a lwB4 gateway in some of our buildings so
could connect directly to the lwB4. Users could access the IPv4 that end device could connect directly to the lwB4. Users access the
Internet through the CNGI IPv6 Network. IPv4 Internet through the China Next Generation Internet (CNGI) IPv6
Network.
2.1. Experimental Environment B.1. Experimental Environment
The network topology for this experiment is depicted in Figure 7. The network topology for this experiment is depicted in Figure 7.
+-----+ ------- --------- +-----+ ------- ---------
|Host1+---+ / \ // \\ |Host1+---+ / \ // \\
+-----+ | // \\ / \ +-----+ | // \\ / \
+-----+ | +--------+ | CNGI IPv6 | +--------+ | | +-----+ | +--------+ | CNGI IPv6 | +--------+ | |
|Host2+---+--+lwB4(AP)+--+--| Network |--+ lwAFTR +---+ IPv4 Internet + |Host2+---+--+lwB4(AP)+--+--| Network |--+ lwAFTR +---+ IPv4 Internet +
+-----+ | +--------+ | \\ // +--------+ | | +-----+ | +--------+ | \\ // +--------+ | |
+-----+ | | \ / (DHCP4o6 Server) \ / +-----+ | | \ / (DHCP4o6 Server) \ /
|Host3+---+ | --+---- \\ // |Host3+---+ | --+---- \\ //
+-----+ | | --------- +-----+ | | ---------
| | | |
+-----+ | | --------- +-----+ | | ---------
|Host4+---+ | | // \\ |Host4+---+ | | // \\
+-----+ | +------+ | | / \ +-----+ | +------+ | | / \
+---+lwB4 +--+ | | | +---+lwB4 +---+ | | |
+-----+ | +------+ +-----------------------+ IPv6 Internet + +-----+ | +------+ +-----------------------+ IPv6 Internet +
|Host5+---+ | | |Host5+---+ | |
+-----+ \ / +-----+ \ /
\\ // \\ //
--------- ---------
Figure 7 Tsinghua University Lightweight 4over6 experiment topology Figure 7 Tsinghua University Lightweight 4over6 Experiment Topology
In this deployment model, lwAFTR is co-located with a DHCP4o6 server In this deployment model, the lwAFTR is co-located with a DHCP4o6
to assign restricted IPv4 address and port set for lwB4. lwAFTR server to assign port-restricted IPv4 addresses and port-sets to the
listens to all DHCPv4 over DHCPv6 messages generated or received by lwB4. The lwAFTR snoops the DHCPv4 over DHCPv6 messages generated or
the DHCP4o6 server and updates its binding table through valid received by the DHCP4o6 server and updates its binding table
messages. accordingly.
In our experiment, the lwB4 gets its IPv6 address through static In our experiment, the lwB4 receives its IPv6 address through static
configuration or dynamic configuration. It will then send a request or dynamic configuration. It then sends a DHCP4o6 request to the
to the lwAFTR device to get the public IPv4 address and its valid lwAFTR device to get the public IPv4 address and valid port-set. The
port set. The lwAFTR will add the IPv6 address, IPv4 address, and lwAFTR will add the IPv6 address, IPv4 address, and port-set
port set information of the lwB4 into its binding table. information of the lwB4 into its binding table.
2.2. Experimental Results B.2. Experimental Results
In our experiment, we tested the performence of various applications, In the Tsinghua University experiment, the performance of various
including web, video, p2p, ping, tracert, telnet, SSH, email. online applications were tested including web (HTTP/HTTPS), email, instant
storage, instant message, online gaming, online payment and so on. messaging, FTP, telnet, SSH, video, Video Camera, P2P, online gaming,
We also tested different terminal devices including PC, laptop and VoIP. We also tested different terminal devices including PC/
computer, and cell phone. These include devices using different laptop computers, and cell phone. These devices used different
operating systems, including Windows 7, MacOS, Android, and IOS. operating systems, including Windows 7, MacOS, Android, and Apple
IOS.
The experimental results are listed as follows: The experimental results were as follows:
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
|Application Type | Test Applications | Test Subjects |Result| |Application Type | Test Applications | Test Subjects |Result|
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
| Web | IE, Chrome, Sougou |Browse websites, | OK | | Web | IE, Chrome, Sougou |Browse websites, | OK |
| | |download files | | | | |download files | |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
| Video | Youku, pptv, qqlive |VOD, live video | OK | | Video | Youku, pptv, qqlive |VOD, live video | OK |
| |(Web based,client based)| | | | |(Web based,client based)| | |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
skipping to change at page 22, line 44 skipping to change at page 22, line 32
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
| Cloud storage | Baidu Cloud |Upload/download files| OK | | Cloud storage | Baidu Cloud |Upload/download files| OK |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
|Instant messaging| Skype, QQ |Send/receive messages| OK | |Instant messaging| Skype, QQ |Send/receive messages| OK |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
|Online gaming | QQ game |Enter game | OK | |Online gaming | QQ game |Enter game | OK |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
|Online payment | JD, Taobao |Complete payment | OK | |Online payment | JD, Taobao |Complete payment | OK |
+-----------------+------------------------+---------------------+------+ +-----------------+------------------------+---------------------+------+
Figure 8 Tsinghua University Lightweight 4over6 experimental result Figure 8 Tsinghua University Lightweight 4over6 experimental result
2.3. Conclusions B.3. Conclusion
Lightweight 4over6 supports the majority of current IPv4 applications Lightweight 4over6 supports the majority of current IPv4 applications
and services. The user experience of using Lightweight 4over6 is no and services. The user experience of using Lightweight 4over6 is no
different from using the native IPv4 network. It can satisfy the different from using the native IPv4 network. It can satisfy the
IPv4 network service demands of IPv6 network users. IPv4 network service demands of IPv6 network users.
Authors' Addresses Authors' Addresses
Qiong Sun Qiong Sun
China Telecom China Telecom
skipping to change at line 923 skipping to change at page 23, line 36
Email: fibrib@gmail.com Email: fibrib@gmail.com
Tianxiang Li Tianxiang Li
Tsinghua University Tsinghua University
Beijing 100084 Beijing 100084
P.R.China P.R.China
Phone: +86-10-6278-5822 Phone: +86-10-6278-5822
Email: peter416733@gmail.com Email: peter416733@gmail.com
Ian Farrer
Deutsche Telekom AG
Bonn 53227
Germany
Email: ian.farrer@telekom.de
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