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Community Member

E1 for voice/data

We have an existing NORTEL PBX in the main branch and a NORSTAR key system in the remote branch, with E1 connection in between provided by the carrier (leased line). There are 100 analog voice users in the main branch and 8 analog voice users in the remote branch. I want to utilize this E1 connection for voice and DATA applications. Please advise the solution. Thanks -rommel-

Community Member

Re: E1 for voice/data

Not really sure what brand of routers you have in between the main site and remote site. If it is Cisco devices then I suggest you go to their website and search for configuring VOIP for the chassis you have. Basically if you are wanting to utilize the E1 instead of any other connection between the two you should be able to specify this with route statements or with policy routes.

Cisco Employee

Re: E1 for voice/data

Assuming this are Cisco gateways unless if you are starting from scratch. You should contact pre-sales to get more advice on specific hardware for this solution. Technically from your description. First thing you must make sure is your IP connectivity is up. It seems you may have max of 8 calls the most on this E1 link. If so you would probably use g729 codec which would take about 28kbps for single VoIP call including the layer 2 header of 6 byte. That means for 8 calls you would require 224 kbps just for voice, rest of the bandwidth you can use for data. The second thing you may want to consider is Qos. You will need to use LLQ to prioritize your voice traffic over data.

Hope this helps..


Community Member

Re: E1 for voice/data

Because you don't say anything about any routers or any other devices capable of pachet switching, I suppose you carry on your E1 link only analog voice. The previous answers point out a VoIP solution...but in the same time you can use for example 2 CISCO 2610 with one VWIC-MFT-2E1-DI interface card on each one of the 2 routers...and beginning from here everything is very simple: a number of timeslots (nx64kbps) from the 30 you have on the E1 link will form a serial interface wich can be used to carry data, and the rest of the 64kbps channels will be cross-connected to the PBX.

This is exactly what I have done with one of our clients which has 2 PBXs connected with an E1 link. Following the same idea, he can now use 1Mbps for data transmission and the rest of the E1 link (14 channels for analog voice). You can adapt this to your needs.

Of course, using this idea you will have fewer simultaneous calls than with VoIP solution, but in the same time you will have the call quality specific to analog calls. (anyway, the maximum number of simultaneous calls you need over the link is 8)...and, of course, you don't have to worry about QoS.

The choice is yours...for example, our client didn't want to implement VoIP.

I have implemented both solutions till now, and I can tell you both of them work nice and smooth...

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