Questions about MRA

[himanshu87]

I have some doubts about MRA but unable to find some concrete answers.

1. What is the need for Expressway E? As i understand it receives requests and forwards it expressway C. Does it does any authentication of the traffic coming to it?

2. How does the RTP flow for a MRA call? Does it hairpins on EXP-C?

3. Call signalling for a new call from a Jabber on Internet to a on Premises Jabber.

4. Where does multipluxing/Demultiplexing takes place

All my queries are related to MRA only.

Thanks

Himanshu

[Jaime Valencia]

Have you reviewed any of the MRA material from Cisco Live??

All of what you're asking is covered there.

This is an example, but there are plenty more sessions

https://www.ciscolive.com/online/connect/sessionDetail.ww?SESSION_ID=82734&tclass=popup

1 No, it just proxies all to CUCM

2 endpoint -> EXP-C -> EXP-E -> endpoint

3 The MRA endpoint is registered to CUCM, CUCM is still the one in control, everything is proxied via EXP-C and EXP-E

[himanshu87]

HI Jamie,

Thanks for replying.

1. If EXP -E just proxies, why do we need to put it there? Is there no purpose for it?

2. EXP E and EXP C just proxy the requests to CUCM. So in this case, anyone on the internet can put false username and correct domain name to reach CUCM. Although the request will get rejected, can this be a source of large requests consuming processor cycles?

3. I wanted to know how signalling will take place when Jabber on internet calls an on premises phone? Since EXP E is the server and C is the client.

Thanks

Himanshu