Trunk lines

Unanswered Question
Jun 11th, 2007
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Hi All ,

Just a quick one, i need to connect 32 Analog trunk lines to a PABX and 4 PRI's to the PSTN. any Suggestions on which Cards i could use on the ISR to achieve this

Thanks in Advance

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Overall Rating: 5 (4 ratings)
paolo bevilacqua Mon, 06/11/2007 - 09:26
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from the PBX point of view, trunk lines are FXO, that is, analog lines that normally go to the pstn. This means the voice gateway will need FXS ports.

If this is your requirement, be aware that the integration may suffer of problems, for example you will not be able to give DID to the PBX.

Anyway, considering the density, the minimum you can use is a 2821 with EVM-HD-8FXS/DID + 2 x EM-HDA-8FXS, 2 x VIC-4FXS, 2 x VWIC2-2T1E1, 1 x PVDM2-32.

Hope this helps, please rate post if it does!

paolo bevilacqua Mon, 06/11/2007 - 14:14
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Woops a small (but expensive) correction. You will actually need 2 x PVDM2-64 for the above, because even if is is an hairpinned configuration, IOS will not let create the voice port if there is not at least 1 DSP resource for each. 23 x 4 + 32 = 124.

This can turn out to be quite an expensive solution for an (apparently) simple task.

Rob Huffman Wed, 06/13/2007 - 06:36
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Hi Paolo,

Nice catch on this one! This really goes to show that you think these scenarios through (I always knew you did) 5 points for your continued great work :)




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