[Asterisk-Users] What is acceptable network latencyforvoipconnection?

[Damon Estep]

> Thanks,
> So what are the fresholds of the jitter, delay, and
> packet loss I should be asking my ISP for?
> robert
> 

On a T1 you should expect an SLA that states;

Latency - < 80ms round trip latency between your end and the ISP core
routers within a few thousand miles, SLAs typically only cover traffic
on the ISPS network. Try to use the same ISP for all VoIP endpoints so
there is never any question about which network the delay occurs on.

Jitter - SLA should be < 5ms

Packet loss - should be < 0.5%

While VoIP might tolerate more jitter and packet loss than stated above,
these are not unreasonable parameters for T1 service and you should be
able to get an SLA that falls in or near these parameters. Any ISP that
can not provide a close SLA is not confident in their network.

In my experience, packet loss is the biggest enemy, jitter is a close
second, and latency is third (if it is still under ~200ms).

Latency is a function of bandwidth and without congestion will be very
consistent on similar bandwidth connections. Increases in latency due to
congestion almost always come with high packet loss and jitter.


Google for T1 Internet SLA and you will see many sample SLAs.