Additional Questions

[Dave McDysan <dave.mcdysan@wcom.com>]

As discussed today, here are some additional questions (and my answers).

Q:Need a definition for Network Hierarchy:

(Here is the one from Bert's DT kickoff note):

  Network Hierarchy:
>    Network hierarchy in this context refers to abstraction of
>    part of a network's topology and the routing and signaling
>    mechanism needed to support the topological abstraction.
>    Abstraction may be used as a mechanism to build large
>    networks or as a technique for enforcing administrative,
>    topological or geographic boundaries. For example, network
>    hierarchy might be used to separate the metropolitan and
>    long-haul regions of a network or to separate the regional
>    and backbone sections of a network.

Q: What are the drivers for network hierarchy?

A: RFC 2547bis BGP/MPLS VPNs, other provider provisioned VPNs based upon
MPLS tunnels (e.g., virtual routers), Pseudo Wire Edge-to-edge Emulation
(PWEEE).

(MPLS) signaling scalability for a large ISP.

Signaling standards that support dynamic establishment and restoration of
LSPs across a 2-level IGP hierarchy.

Management of the level of traffic engineering and routing information in a
large ISP.



Dave