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New Member

trying to put data across the IP Telephony backup links.

Hi All,

The company I work for is in the middle of an IP Telephony rollout.

The Branch offices connect back into the main office via 2Mb links.

The IP Telephony backup is via an ISDN Onramp10 service. The Onramp10 service is an E1 PRI based ISDN service in Australia.

The Voice Gateway routers that were recommended were built around the following:

Cisco 3725





The routers also have BRI interfaces for out-of-band management and as backup links for critical network data.

My question is:... If we were to replace the WVIC-1MFT-E1 card with a VWIC-2MFT-E1-DI card; could we then share the onRamp10 ISDN channels between voice and data when the 2Mb primary link failed?

I have an info sheet for the Multiflex VOICE/WAN interface.

If anyone has had any experience using ISDN services to backup IPTel and network data; I would really like to hear from you.

thanks very much,



Re: trying to put data across the IP Telephony backup links.

you can setup the BRI to provide data services. this includes handling the voice calls between the branch and main office.

once an point-to-point IP link is established, you can pass VoIP traffic over it whether it's PRI, WAN or BRI. the BRI must be provisioned for data by the telco. this could be configured as onDemandRouting for when the main link goes down.

this can also be setup to have two routes with different costs between the sites. when the lower cost route, (main link), is out of service, the higher cost route, (BRI), could be used.

see these links for more info:

New Member

Re: trying to put data across the IP Telephony backup links.

Hi and Thanks very much for your reply.

We have been using the BRI ports as a data backup port. We are finding that the 128K aggregated bandwidth on the BRI might not be enough.

I was really hoping to be able to use the Onramp10 service installed for Voice only on the routers for data as well.

Thanks for the tip about calling the Telco. We will definately have to call the Telco and have the link provisioned both for voice and data.

I am concerned over the choice of line card that the PRI service will be plugged into. The VWIC-1MFT-E1 card handles voice only.

I was hoping I could replace that card with the WVIC-1MFT-E1 card. I read some documentation on the card and it seems to handle voice and data using a drop and insert method.

I am not quite sure that this will work though. Unfortunately, I have very little experience with IP Telephony. (learning everyday though :)

In the long run, it would be nice for us to decomission the BRI links and keep the Onramp10 links carrying voice and data.

Thanks again for your help

I did some reading