Expressway-E/C Cluster max proxied registration

[Georg Kehrer]

Dear all

I have seen in the Datasheet if we have Expressway Cluster with 6 , the capacity will increase to maximum of 10'000 proxied registration

Is that correct If build a cluster with 2 the capacity will be increase to 5000 ? or less ? 

Clustered Cisco Expressway capacity

●  Up to 6 Cisco Expressway appliances and virtual machines can be deployed as a clust to increase capacity and provide redundancy ●  Clustering increases the maximum call capacity by up to 4 times

has anybody Idea whats the reason?

Thanks for any Feedback.

Best Regards

Georg

[Patrick Sparkman]

The total capacity for an Expressway cluster of 6 (the max) will actually be 15000, as each single Expressway is capable of handling up to 2500 proxied registrations, no matter deployment size (small/medium/large) or cluster size.

So for a cluster of two (2) Expressways, you can have 2500 proxied registrations on each individual server, for a total of 5000 across the two servers.

[Georg Kehrer]

Hi Patrick

Thanks for the Feedback.

But why cisco are telling max call capacity by up to 4 times?

form which release did this change?

Regards

Georg

[Chris Swinney]

Hi Patrick,

Is it also true that in a 6 cluster VCS, two of the VCS's are actually hot slaves. Whilst they add the overall licensing, only 4 will be active a one time and as such only support the 10,000 registrations?

Just a thought.

Cheers

Chris

[Patrick Sparkman]

Chris -

Yes, I forgot in a cluster of 6, only 4 are active at any one time.  So 10000 registrations across the cluster in a small/medium deployment and 20000 for large, as the 2 remaining cluster peers are on standby not being used unless one of the 4 active peers goes down.

[Georg Kehrer]

Ok so we have with 2 clusters 5000 ?

[Patrick Sparkman · Accepted solution]

Georg -

I was just about to reply to your comment, but I wanted to look up something first and actually found an issue with the data sheet that my very first reply was based on.

I'm going to assume when you mention "2 clusters", you're referring to a cluster of 2 servers.

According to the data sheet, a VCS using the small/medium/large deployment size can have up to 2500 registrations on each server in a cluster, for a cluster of two (2), you'd have up to 5000.

The admin guide says a VCS using the small/medium deployment size can have up to 2500 registrations on each server in a cluster, for a cluster of two (2), you'd have up to 5000.  However, a VCS using the large deployment size can have up to 5000 registrations on each server in a cluster, for a cluster of two (2), you'd have up to 10000.

Regarding the data sheet and admin guide differences, I'd go by the admin guide.  To me, it wouldn't make sense to provide a large deployment version of the VCS and keep it's capacity the same as the small versions.

The VCS Admin Guide on pg 202 lists the above information.

[Georg Kehrer]

Hi Patrick

Thank for the clarification, now is clear for me the important point was that 2 Server are standby.

Regards

Georg

[Chris Swinney]

Hey Georg,

You only get standby servers when you have a cluster with more than 4 devices. So you can have a cluster of 4, then all four will be active and provide you with the figures listed. If you add one more server to the cluster, you will still have 4 active, and now 1 as a standby. If you add another, you will still have 4 active, but now 2 standby.

You don't get much benefit from have the 5th and 6th server in the cluster other than super higher resilience.

Cheers

Chris

[Patrick Sparkman]

As Chris pointed out in his reply, in a full VCS cluster of 6 servers, only 4 are active at any one time, the remaining 2 are in standby until needed if one of the active servers goes down.  That is why they say, the capacity is increased by 4 times, 4 being the VCS servers that are active.

It's always been this way to my knowledge.