Subject: [DMM] Comments on I-D: draft-matsushima-stateless-uplane-vepc

From: Basavaraj Patil <[email-masked]>
Date: Fri, 26 Jul 2013 16:06:15 -0500

Hi Ryuji,

Good to see a new approach to mobility for the evolved packet core
architecture. At the very high level it is using standard mobility
signaling but then enabling seamless mobility (with session continuity
etc.) without the need for tunnelling the user plane.

Comments:

- The benefits of moving the mobility functions (MME/SGW/PGW) to the
  cloud are very valid. Operators have a much greater degree of
  flexibility in terms of capacity and can add or shrink depending on
  the requirements and this allow for deployments that scale with
  growth of subscribers, traffic etc. It also allows operators to be
  decoupled from specific vendors of the mobility applicances (but
  instead will have to rely on vEPC providers).

- I wonder if there are any examples or research papers showing the
  implementation of EPC functions such as MME, S/PGW on a hypervisor.

- It is crtitical that the functions deployed in the NFV are
  interoperable and hence the need to have specifications.

- The intent of using BGP for routing user plane traffic is
  interesting. How about the scalability aspect? Have you done any
  studies on this given that an EPC could be serving many millions of
  nodes.

- What about the handover performance? Since the EPC-E router needs to
  be updated with the new address, does that affect HO performance for
  real-time applications?

- Backward compatibility will be essential in order to allow for
  operators to deploy a new architecture like the vEPC while allowing
  the ability to interwork or roam in networks that do not have the
  same capability.

The proposal looks promising and worth working on in the IETF.

-Raj

-- 
Basavaraj Patil