Lots of E1's on a 2911

benc · ‎06-02-2016

Hi All,

looking at doing 8x E1 handoff on a Cisco 2911 and looking for feedback if this is infact ok ?

Build of materials would be:

Cisco 2911 Voice Feature set.

4x VWIC3-2MFT-T1/E1

2x PVDM3-128

Essentially doing SIP handoff on a site - using straight G711

From everything i can find i should be able to do all 8 E1's off one 2911.. Being all 256 Channels

Using one group for all 8x E1's too.

Thanks

Philip D'Ath · ‎06-04-2016

Although I think you'll be able to configure everything and get it working, I'm not very confident that the 2911 will have enough CPU grunt when the system is at full load. And because you are processing SIP traffic, that might cause random latency in your VoIP traffic - just what a VoIP provider wants (not).

If it was me I would probably look at a 4000 series router, and an 8 port E1 card (NIM-8CE1T1-PRI). I quite like the 4331. You can triple the performance of this router with just a licence upgrade.

http://www.cisco.com/c/en/us/products/routers/4000-series-integrated-services-routers-isr/models-comparison.html

http://www.cisco.com/c/en/us/products/collateral/routers/4000-series-integrated-services-routers-isr/data_sheet_c78-728308.html

Philip D'Ath · ‎06-04-2016

ps. The 4000 series is what replaced the 2900/3900 series. You shouldn't be buying new 2900/3900's any more.

ADAM CRISP · ‎06-10-2016

Re CPU->

I have seen old c2821 routers with 6x E1's. Absolutely flat out with plenty of calls being setup and torn down we see CPU levels around 60% with no measurable change in call setup time / call quality. Given the performance hike when stepping up to a c2900, I would have no concern about having 8 E1's in a chassis, so long as there are the available resources (PVDM) and assuming there are no programmatic restrictions inside IOS.

It might be better to split the E1's over two chassis as maintenance is easier if you have more flexibility when restarting systems.

Adam

Philip D'Ath · ‎06-10-2016

A 2821 is much faster and a 2811, and this is a 2911.

Tagir Temirgaliyev · ‎06-12-2016

sorry,

you mean 2821 is faster than 2911 ?

Philip D'Ath · ‎06-12-2016

It's not clear to be the relative performance difference between a 2821 and a 2911. A 2911 may not be faster than a 2821.

benc · ‎06-05-2016

Thanks..

Surprised to see/hear the CPU toping out - doesn't the DSP offload all the work ? leaving just the signalling to the CPU ?

i was hoping to use refurb commodity bits readily available.

I have a few sites requiring 16 E's and another few sites with 8x E1 handoff.

How about cisco 7206-G1's with PA-MCX-4TE1 or PA-MCX-8TE1 ?

or are these way too old ?

ive also done a bit with AS5400's - which seem to be ok..

Philip D'Ath · ‎06-05-2016

Correct, it should only be doing signalling.

If you have other sites running 8 to 16 E1 handoffs on a 2911 then you will have no issue.