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Mobile Voice Access Doubts

Hello everybody,

I followed some documentation to configure MVA, and it is working fine. I did some tests and I could make it work using harpinning or not... For the E1 R2-Digital links I used hairpinning and for E1 ISDN PRI links I could make it without hairpinning.

But I have some doubts regarding the implemantation...

1) Why do I need to use hairpinning if using R2-Digital links?

2) Every document I read say I should have a MVA DID and a MVA DN. What's the difference between them? I know the DID is the number someone from PSTN should dial to reach the application, but what about the MVA DN I configure in Media Resource? And why should they be different from each other?

Thank you!


Cisco Employee

Whats MVA DID?

Whats MVA Number?

Here's why we have two conventions

Lets say we have a CUCM cluster servicing users in 10 different countries.

So we need 10 different local MVA Numbers so that users can dial-in locally right?.

These numbers are the MVA DIDs.

Btut.. the point to be noted here is Single CUCM Cluster can only have ONE MVA DN(MVA Number). So at each site, we will have h323/SIP Gateway, where when calls come in on the MVA DID(Local PSTN Number) we invoke the service Mva on the dial-peer.

We will need to translate MVA DID --> MVA DN, which then matches a MVA outgoing voip dial-peer with

dial-peer voice 1 voip

destination patter (MVA_DN)

session-target CUCM

So once the User is authenticated via VXML, and once the called number is collected , the GW will establish a voip leg to the MVA number on the CUCM


PS:Rate useful posts


Thank you!!! It was really helpful!

But the weird thing is that I have the following dial-peers on my H.323 gateway:

dial-peer voice 4499 pots
service ccm
incoming called-number 4499

dial-peer voice 44991 voip
destination-pattern 2499
  session target ipv4:
dtmf-relay h245-alphanumeric
codec g711ulaw
no vad

So the MVA DID is 4499 (this is the number sent by the carrier) and the MVA DN is 2499.

In CUCM, the ext. 2499 is configured in Media Resources and 4499 is configured in Service Parameters.

No translation patterns were created. And it is working fine like this.

So for testing purposes, I removed the dial-peer 44991. And it keeps working!

Shouldn't it be unable to complete the call?


Hi dijohn

Can you please help me in detail to configure MVA for different sites.

My setup is like below,

CUCM cluster at Site - A (MVA configured with DID number using H323 gateway & working fine)

I want to configure DID number from site B as a MVA number for users at site B. (I have MGCP gateway & need to hairpining for site B)

How can i configure this so that my users at site B can dial local DID number & access MVA?

Since in india TRAI regulation says i should not merge VOIP & PSTN calls.

Please help on this in detail. If you have any specific document or configuration, pls share.

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