VOIP and ISDN

[mikeatquick]

Being new to VOIP I am having difficulties using VOIP and other internet traffic. I am using Vonage as the VOIP service and have used their configuration to throttle back the bandwidth to 30. I have a Netgear RT338 router connected to a 10/100 switch. Plus, I am using a Ciso ATA 186 for the vioce interface. All connections to the router are 100meg. If I have a VOIP call in progress and have any internet traffic the voice conversation becomes choppy. I need to know if there is a way on this router to give the VOIP traffic priority or a dedicated portion of the bandwidth. Or is there a way to limit the bandwidth for other internet traffic? Multiple test sites show a speed of 113 to 117 both up and down (I am using multiple channels). Is there anything else I should check beside pure speed (pakets, latency etc.)? If I should check anything else, where can I check this?

If there is no solution for this configuration, is there one using a Cisco 804 router?

This is a small network with just 3 users and the ATA 186. I know a faster connection would be prefferable but, living in the rural areas means you work with what you have.

 

[ciscoexpert]

So are you trying VoIP over internet ? Well I dont guarantee any QoS on that.

Note that QoS needs to be end to end, and it needs to be provided on all the routers that the packet is passing through.

I am not sure about the Netgaer router, whether you can do an QoS on it. Am no Netgear expert!

But yes on the Cisco, you have tons of options to do QoS, to allocate specific bandwidth for calls going out.

Also on the ATA186, see if you can set the codec for voice transmission to g729, so that it uses only 8 kbps bandwidth, per call,unlike g711 which uses 64 kbps.

Hope that helps!

Sankar Nair
General Datatech l.p.

http://www.generaldatatech.com

 

[mikeatquick]

I have found no way to set up QOS on the Cisco 804 ISDN. Also, how would I change the codec on the ATA. This is a little beyond my normal expertise.

 

[ciscoexpert]

Mike,

I apologize, probably I overlooked...hmm ISDN interface doesnt support that many qos features for voip, unlike other interfaces. (serial, atm etc). I havent had a chance to look up the ATA configs to change the codec. I will let you know.

Sankar Nair
General Datatech l.p.

http://www.generaldatatech.com

 

[rapples]

I think the reason Vonage works as well as it does is because they have peering arrangements with the major broadband providers.

Anyone know anything about this? Who's your internet service provider?

 

[ts1973]

using the wrong codec can make this happen. For instance if you were using G.711 with 10 millisecond samples your total bandwidth requirements would be over 121 Kbs which is more than you have. What codec is your voip endpoint using ?