Minimum Requirements for VoIP on LAN

[jeff]

I'm just starting out with understanding VoIP and the related Cisco products, but I would like to setup a local IP telephony system here in our office. What are the minimum hardware/software requirements to setup a couple of Cisco 7960 or 7940 IP phones on our LAN switched network?

Thanks for any help.

Jeff

[pwalenta]

Every new Cisco switch supports their IP Phones.

This includes 295X, 35XX, 4XXX, and 65XX series switches. I'd recommend a 3560-24 w/inline power so you don't need to use power bricks with the phones.

As for traffic, by default the phones use 80k per active call (a pittance of traffic for a LAN these days). As far as software goes, you'd need a server running some version of CallManager - I'd recommend CallManager version 3.3.4 (it has some newer features, and seems a little more stable than earlier 3.3 versions). If you want to get calls from "the outside", you will need some sort of gateway to the PSTN or a local PBX. I'd recommend a 1760V which can do many of the smaller ports (use the 2 port cards only, 4 port cards have static issues), it can also do voice T1's.

[jeff]

Thank you for the reply.

What would make the Cisco switches you mentioned better for IP phones? Isn't the traffice just RTP voice packets that would route/switch over the network? The server for CallManager, is this a Windows server running this software that's connected to the same network as the IP phones?

Thanks for your help. Can you recommend any entry level reading for me so I can understand the hardware/software needed to setup a basic configuration and will guide me to going further than just two local phones.

Jeff

[jbrind · Accepted solution]

Jeff,

the reason those switches were recommended is that they support QOS and also 802.1q vlan support for the Cisco IPPhones. This means you can use one wire to the desktop, ie. from the switch to the IPPhone then from the phone to the PC. The vlan support allows you to send the voice and pc traffic down different vlan tagging therefore making sure voice has a QOS. Yes callmanager runs on windows and it would sit in the the same subnet as the IPPhones, and the pc data would sit in there subnet.

There/s plenty of reading out there to read, u just need to get stuck in !!

Have u considere'd CallManager Express ? this is a IOS version of callmanger, and would be far cheaper to set up if yopu are just experimenting ! something like a 1760-v could run this IOS

[jeff]

Thanks for the info. I would consider CallManager Express, since I have been looking into it for my testing and hands-on experience. The CallManager Express runs on the router in IOS? Does this mean when using the Express version a windows server is not needed?

Thanks again for your help.

Jeff

[pbarman · Accepted solution]

You do not need a Windows server to run CallManager Express (CCME). CCME is a IOS feature, and will run as a telephony-service on the IOS router. Not all routers and IOS support the feature. Below are two links to give a understanding of the feature, how it works and on what platforms and IOS it is supported.

http://www.cisco.com/univercd/cc/td/doc/product/access/ip_ph/ip_ks/cme31/cme31spc.htm

http://www.cisco.com/univercd/cc/td/doc/product/software/ios123/123newft/123t/123t_7/cme31sa/index.htm

[jeff]

Thank you for the information.

[jbrind · Accepted solution]

This is correct, you will not need a Windows server. Callmanager express runs on IOS u will just need a lic for it. Also as you are new to setting this up CallManager Express has a web page gui for the set up.

[jeff]

Thank you for the reply. I look forward to setting this up on my network.

Thanks again.

Jeff