Proxy Mobile IPv6


Proxy Mobile IPv6 is a network-based mobility management protocol standardized by IETF and is specified in RFC 5213. It is a protocol for building a common and access technology independent of mobile core networks, accommodating various access technologies such as WiMAX, 3GPP, 3GPP2 and WLAN based access architectures. Proxy Mobile IPv6 is the only network-based mobility management protocol standardized by IETF.

Introduction

Network-based mobility management enables the same functionality as Mobile IP, without any modifications to the host's TCP/IP Protocol stack. With PMIP the host can change its point-of-attachment to the Internet without changing its IP address. Contrary to Mobile IP approach, this functionality is implemented by the network, which is responsible for tracking the movements of the host and initiating the required mobility signalling on its behalf. However, in case the mobility involves different network interfaces, the host needs modifications similar to Mobile IP in order to maintain the same IP address across different interfaces.
The "SaMOG" study item in 3GPP defines the interworking between mobile packet core and a trusted WLAN access network. The interface that SaMOG defines for this interworking is the 3GPP S2a GTP interface.

Proxy Mobile IPv6 Deployment Models

+--------+ _----_ | +--------+ _----_
| | __ | | | __
| |---- | | |----
| | | | |
| | '----' | | | '----'
+--------+ | +--------+
| | |
-- -- --- -- -- | _----_
-- -- | __
-- -- |
-- IP Network -- |
-- -- | '----'
-- -- | |
-- -- --- -- -- | +-----------+
/ \ | | MAG |----
+-------------+ +-------------+ | +-----------+ |---
| | | | | | LMA |----
| MAG | | MAG | | +-----------+
| | | | | |
+-------------+ +-------------+ | _----_
| | | | | __
+-----+ +-----+ +-----+ +-----+ | ----
| AP | | AP | | AP | | AP | | | |
| | | | | | | | | | '----' |
+-----+ +-----+ +-----+ +-----+ | +-----+ +-----+
. . . . | | MAG | | MAG |
/ \ / \ / \ / \ | +-----+ +-----+
MN | /\
| MN
|
Proxy Mobile IPv6: Flat Domain Model | Proxy Mobile IPv6: Domain Chaining
|

Key Properties of Proxy Mobile IPv6 Technology

Functional Entities

The PMIPv6 architecture defines following functional entities:

Protocol Operation

  1. A mobile host enters a PMIP domain
  2. A Mobile Access Gateway on that link checks host authorization
  3. A mobile host obtains an IP address
  4. A Mobile Access Gateway updates a Local Mobility Anchor about the current location of a host
  5. Both MAG and LMA create a bi-directional tunnel
  6. A Mobile Access Gateway sends a Router Advertise message to MN with Care-of-Address

    Access Authentication

Mobile Operators today are facing two fundamental challenges:
To address these scaling challenges, mobile operators are exploring new technology approaches for expanding their network coverage by integrating alternative access technologies into a common mobile core. Specifically, Wireless LAN networks based on IEEE 802.11 standards is showing lot of promise.
Secondly, for addressing the issue with the massive growth in mobile data traffic, mobile operators are exploring new ways to offload some of the IP traffic flows at the nearest WLAN access edge wherever there is an internet peering point, as opposed to carrying it all the way to the mobility anchor in the home network. Not all IP traffic needs to be routed back to the home network; some of the non-essential traffic which does not require IP mobility support can be offloaded at the access edge gateway. This approach provides greater leverage and efficient usage of the mobile packet core with increased overall network capacity and by lowering transport costs. Approaches such as, Selective IP Traffic Offload Option can be provide the basic offload semantics.

How to Implement Proxy Mobile IPv6

Mobile Access Gateway

Local Mobility Anchor

Proxy Mobile IPv6 Implementations

Internet Standards (IETF)