The issue Andrew and Tony were raising was a bit more simple
and a bit more complicated on several fronts. Let's start
with a picture:
MAE-WEST PBNAP MAE-EAST
39.0/10 39.64/10 39.128/10
A------| S----| A--|
S------| M----| S--|
M------| N9---| M--|
N9-----| NE---| N9-|
NE-----| Y----| NE-|
X------| Z--|
In normal conditions:
How does X get traffic to Y?
How does Y get traffic to X?
How does X get traffic to Z?
How does Z get traffic to X?
How does Y get traffic to Z?
How does Z get traffic to Y?
How does A get traffic to Y?
How does Y get traffic to A?
Where can 39.0/9 be aggregated?
Where can 39/8 be aggregated?
What are the side-effects of both these aggregations
when things are operating normally?
In failure conditions:
If S falls off MAE-WEST, how does it get traffic
to the customers of A, M, N9, NE and X that are
addressed by 39.0/10?
How do A, M, N9, NE, and X get to S's customers
that are addressed by 39.0/10?
If A falls off MAE-WEST, how does it get traffic
to the customers of A, M, N9, NE, and X
that are in 39.0/10? How does it get to all of 39.0/9?
How does the rest of the world get to A's customers
that are addressed in 39.0/10?
What happens in both these cases to traffic between Z
and everything in 39.0/9, in each direction?
These definitely are not hypothetical questions.
If geographical or stratum-based allocation that is not
_also_ provider-based is to fly, this is precisely the type
of thing that must be dealt with.
Sean.