Voip over ADSL

[kalman]

Hi

i see that cisco ship whit the 827-4v adsl voice router foe little customer. my question is : can the adsl net grant the necessary layer 2 performancem latency,fragmentation,caching,etc... to obtain a good voice quality? whitch QoS can help? same example?

thanx

Luigi

Italy

[thomas.chen]

You can’t guarantee QoS SLA’s over the Internet but you can have your DSL connect you directly to the corporate network. Your SP should be able to provide SLA’s on that setup.

[memam]

What are the upstream and the downstream bit rates you are working on?

[firthr]

I have a Cisco 7940 IP phone and use it with ADSL (512/128) The 7940 has a built in switch, so I plug the network PCs in the 100mb switch port and the 7940 in the ADSL router. The phone set all VoIP packets to have IP Precendece of Flash (very high) which takes priority over the other traffic. I'm in the UK, the Cisco Call Manager is in the US and it works very well even running G.729 compression/codec. Some deterioration is noticable if I call an off network PSTN number however, but IP phone to IP phone is great.

Regards

Richard