Cisco 3945

Hey all,

I'm hoping some of you voice guys can answer some basic questions for me. I'm looking to upgrade my current routers from 2811 to 3945s. However, as an added bonus my boss is looking to do SIP trunking with our carrier. We're a Nortel shop when it comes to our voice, so for now we plan on doing SIP from the carrier to us, then possibly using this 3945 to convert to TDM and send to the switch.

Our current trunking comes in on a DS3 (only partial, we don't max it out). I'm pretty sure the 3945 will handle it, but I don't know for certain. What sort of modules would I need for this, and does it seem feasible?

Thanks

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shodown

Yes the 3945 will handle a D3 with ease you can actually fit 2 in there. My question for you is what type of hand off are you getting. You can get a Ethernet hand off and use a cheaper router. Also be aware of the dangers of SIP if you are a high call volume user. The big carriers don't have the SIP experts that some of the true ITSP's have

burbankmarc

Well we are a call center so the calls are our bread and butter. Currently we have an ethernet hand-off. We have 2 PBXs in 2 different facilities. The logic of going to SIP is so we can move our local numbers from one facility to the other for maintenance, and emergencies. Right now we can't do that, so if our main facility fails, we lose all of our local numbers here which causes down time for our customers.

We're currently using 2811s but I seem to be pushing them to their limit. Their CPU utilization is a steady 60-70% and pegs into the upper 90s frequently. Hence the upgrade to a bigger box.

shodown

SIP is not ready for prime time with call centers yet. We are still at least another year off unless you get with a good carrier. We have done some small 15-20 seat call centers with sip and still have a PRI backup just in case and we've had to use it more than once. If you are much larger than that I would suggest using a PRI right now or going to a carrier that specializes in SIP.

As for your HIGH CPU the 3945 should meet all your needs, it will be a tad bit on the overkill side, but better to have more than less. Just be carefull on the SIP setup. Test it out with setups who aren't critical for the call center like the IT department, and so on and slowly merge it into your call center DO NOT DO A FORK LIFT UPGRADE to SIP. One of my clients got a pretty hefty bill from us due to me doing around 50 hours of re design work on the fly and after hours trying to get him working. SIP will require you to take a look at DSP's, call routing, IP routing, dial-peers and so on. Good luck. With a well thought out and phased plan you can make the transition.

sieff

If you're looking to have a carrier grade termination for DS3's and SIP that would allow future growth it may be best to go with an ASR 1000 series. There's also a Cisco VGD 1 T3 Voice Gateway, which may fit nicely. You're experience with SIP largely depends on your ITSP. If the SIP provider doesn't have a standard configuration guide for your SIP configuration I'd be leary. I've had some providers that were excellent and I've had some where I've had endless night after night of pulling my hair out. One more thing, if you find that this is going to be a risky conversion I'd suggest contracting a Cisco Gold Partner that has good references and local expertise. It may turn out to be a more efficient approach.

shodown

sieff wrote: »

If you're looking to have a carrier grade termination for DS3's and SIP that would allow future growth it may be best to go with an ASR 1000 series. There's also a Cisco VGD 1 T3 Voice Gateway, which may fit nicely. You're experience with SIP largely depends on your ITSP. If the SIP provider doesn't have a standard configuration guide for your SIP configuration I'd be leary. I've had some providers that were excellent and I've had some where I've had endless night after night of pulling my hair out. One more thing, if you find that this is going to be a risky conversion I'd suggest contracting a Cisco Gold Partner that has good references and local expertise. It may turn out to be a more efficient approach.

He has already been talking to one online