User's Manual

29/OCT/2014 REVIEW DRAFT — CISCO CONFIDENTIAL
5-8
Cisco IR500 Series WPAN Gateway and Range Extender Installation and Configuration Guide
Chapter 5 Operation and Configuration
Information about Raw Socket Transport and MAP-T
MAP-T
6LoWPAN is an IPv6-only adaptation layer for the physical (PHY) and media access control (MAC)
layer technologies implementing it. No IPv4 adaptation layer is defined for these PHY and MAC layers,
so the Mapping of Address and Port using Translation (MAP-T) architecture is used as an IPv4-IPv6
translation mechanism. The “mapping of address and port” mechanism defines how IPv4 nodes can
communicate over an IPv6-only infrastructure.
MAP-T was developed as a transition mechanism due to IPv
4 address e
xhaustion, MAP-T is based on a
double stateless NAT64 translation. It specifies a stateless algorithmic address and transport layer port
mapping scheme, and allows embedding of IPv4 address and port numbers in an IPv6 address when
forwarding the IPv4 traffic across an IPv6-only network.
The use of MAP-T in the WPAN gateway enables the use of a same address, if required by a customer,
on the atta
ched f
ield devices since IPv4 traffic coming through the Ethernet port will go through NAT44.
By using MAP-T, the WPAN gateway is using an open standard to integrate non-IP and IPv4
communications over 6LOWPAN/RPL networks.
In a Field Area Network (FAN) scenario, where hund
reds of WPAN
gateways are deployed across
multiple Field Area Routers (FARs), such as CGR 1000, a MAP-T domain begins at the WPAN gateway
level and ends with the head-end aggregation routers, such as ASR1000 as shown in Figure 5-6.