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Gateway for IP Telephony ????

HI ,

Need to know the basic requirement for designing a router as a gateway to the PSTN. I need only 30 PRI lines ie E1

No analog lines on the router. Can a cisco 1721 router with ip plus software and VWIC-1MFT-E1 support my requirements OR do I need a 1751-V or 1760-V router with the VWIC -1MFT-E1 and the PVDM-256-20HD ???? Confused whether i need the PVDM module ......

The router will be the gateway to the PSTN network for my IP telephony LAN network.

Thanks

Rgds

Renzil

1 REPLY
Silver

Re: Gateway for IP Telephony ????

!721 is not voice capable, so you are out of luck here !

The PVDM is a small circuit board that contains the DSP's (Digital Signal Processors) - these are used to compress and packetise the voice traffic. You need them to run voice.

To handle a full E1's worth of voice calls with G711 or G729 codec you would need a 1751 or 1760 router with IP Plus software and a PVDM-256-20HD. This particular PVDM has 5 DSP's that support 6 calls per DSP when running a G711 or G729 codec , refer here for more information -

http://www.cisco.com/warp/public/788/products/1750-vic-issues.html

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