Subject: [rrg] Summary of a layered mapping system based on separation

From: Charrie Sun <[email-masked]>
Date: Sun, 20 Dec 2009 08:12:24 +0800

Proposal: Build a hierarchical mapping system to aid edge-core separation.

Key ideas:

Build a hierarchical mapping system to support scalability, analyze the
design constraints and present an explicit system structure; design a
two-cache mechanism on ingress tunneling router (ITR) to gain low request
delay and facilitate data validation. Tunneling and mapping are done at core
and no change needed on edge networks. Mapping system is run by interest
groups independent of ISP, which conforms to economical model and can be
voluntarily adopted by various networks. Mapping system can also be
constructed stepwise, especially in the IPv6 scenario.

Gains:

1.       Scalability:

a.       Distributed storage of mapping data avoids central storage of
massive data; restrict updates within local areas;

b.      Cache mechanism in ITR reduces request loads on mapping system
reasonably.

2.       Deployability:

a.       No change on edge works; only tunneling in core routers; new
devices in core networks;

b.      Mapping system can be constructed stepwise: a mapping node needn’t
be constructed if none of its responsible ELOCs is allocated. This makes
sense especially for IPv6.

c.       Conform to economic model: mapping system can profit from their
services; core routers and edge networks are willing to join the circle,
either to avoid router upgrades or realize traffic engineering. Benefits
from joining are independent of the scheme’s implementation scale.

3.       Low request delay: Low layer number of the mapping structure and
two-stage cache can well achieve low request delay.

4.       Data consistency: Two-stage cache enables ITR to update data in the
map cache conveniently.

5.       Traffic engineering support: Edge networks inform mapping system
their mappings with all upstream routers with different priority, thus to
control their ingress flows.

Costs:

1.       Deployment of LMS needs to be further discussed.

2.       The structure of mapping system needs to be refined according to
practical circumstances.

Documents

Summary:
http://docs.google.com/Doc?docid=0AQsJc7A4NTgeZGM3Y3o1NzVfNmd3eGRzNGhi&hl=en

Document:

http://docs.google.com/fileview?id=0BwsJc7A4NTgeOTYzMjFlOGEtYzA4OC00NTM0LTg5ZjktNmFkYzBhNWJhMWEy&hl=en