VCS SubZones

[David Anstee]

Creating a complex configuration of VCS with SubZones, Links and Pipes to restrict bandwidths between sites, I understand that the inbuilt VCS logic for call processing between SubZones is to take the shortest path first.

i.e.

SubZone1 --Link--> SubZone2 --Link--> SubZone3

SubZone1 --Link--> SubZone3                                                : Shortest path = call processing route

But what happens in a situation where a SubZone has equal distance to a SubZone, how do we determine which route it takes? I know I could add an extra hop by creating a SubZone between one route to make it longer and force the call process, but wondered if there was a more elegant way, and what the inbuilt logic was for VCS in such a situation?

SubZone1 --Link--> SubZone2 --Link--> SubZone4

SubZone1 --Link--> SubZone3 --Link--> SubZone4                    : What happens?

And another question - at the moment the behaviour of VCS is that the call process happens, and if no bandwidth is available the call will fail, it will not search for alternative routes (links/subzones) with available bandwidth can this behaviour be changed?

Any help with this is appreciated.

[David Anstee]

Bump

[awinter2 · Accepted solution]

Hi David,

it is correct that the VCS will always choose the shortest path. If multiple path exists with the same amount of "hops", the VCS will choose the same path every time. As far as I know, the path the VCS chooses is determined by which index the next-hop (sub)zone has, and you can see the order of these subzones in the 'xConfiguration' output on the VCS.

In other words, the VCS does not take bandwidth characteristics into account when choosing the route, even in the case where multiple paths of same length exist.

Also, the VCS will not fall back to a longer path if no available bandwidth exists for the shortest path(s).

To verify which path a call between two (sub)zones will take, you can use the 'xCommand CheckBandwidth' command from the VCS CLI, for instance

xCommand CheckBandwidth SubZone1 Subzone4 1024 NonTraversal

for simulating a 1 meg non-traversal call between Subzone 1 and Subzone 4.

If you have an interest in changing this behavior or having more means of configuring this on the VCS, a feature request would be the way to go.

Hope this helps,

Andreas

[David Anstee]

Thanks Andreas, I was after that confirmation.

I was trying to build a logical bandwidth topology around the real physical topology, but looks like I need to rethink

Thanks for the clarification