Phone / Gateway Setup - Remote Location

[adamtodd16]

We have an office in an extremely remote location that connects to the Internet using a Satelittle connection. The average response time from this office to our core office is approx 800-1200ms on average.

Currently, we have an 1811 in place, which has a voice and data vlan. The voice vlan has a vpn tunnel setup directly to our core, where the phones register with call manager. There are no phone lines / voice gateway at the remote office.

This is not the ideal setup as we have serious voice quality issues, etc. Just wanted to start a discussion on some options for the ideal setup at this location (SIP TRUNK, VOCIE GATEWAY, CM EXPRESS, other?)

Look forward to hearing some ideas / opinions.

[acampbell]

Hi,

You are away outside the limits for VOIP

Minimize delay between Cisco UCM and remote locations to reduce voice cutthrough
delays (also known as clipping ).

The ITU-T G.114 recommendation specifies a 150 ms maximum one way.

I can see how you can make this sound good at 800-1200 msecs

Looks like you would need to use CME at the remote site as a stanalone and use the PSTN to call outside

Regards

Alex

[Aaron Harrison]

I'd agree - you can use CME for the remote site, thereby keeping the SCCP traffic local.

For calls to HQ etc you can route via the PSTN, or set up a SIP trunk abck to the CUCM and try your luck. I've seen SIP trunks work acceptably with <2 sec call setup time on WANs running 600-700ms latency one way. Once calls were running there weren't any major issues though I expected to get problems due to the delay (i.e. people talking over each other etc).

H.323 by comparison would take around 7-8 seconds on the same WAN. SCCP is pretty chatty so I would expect significant delays in most things - getting dial tone, dialling numbers, etc...

Aaron