What is the quality of "off-net calls"

[d.gautschi]

When I offered a VoIP solution for a corporate multiservice network, the IT Manager expressed a concern for the voice quality of the IP to PSTN (and vice versa) calls.

I am sure the are many existing implementations out there, so what is your experience with VoIP Gateways?

[curtis.starnes]

We are currently running app 150 IP Phones and are using 2 digital gateways (Cisco DT24+) connected to SouthWestern Bell via 2 PRI trunks.

We have had no complaints of the quality of the calls made to the PSTN world...

The digital gateways can be fine tuned to provide the best quality possible...

[mtashiro]

We have installed serveral VoIP solutions and we use IP Telephony in house as well. Our implementations use the following gateways: VG200, DT24+ and 3640's with both T1/PRI and FX cards.

There have not been any voice quality concerns. Just remember when implementing VoIP or IP Telephony, if your LAN or WAN is in bad shape quality calls may be an issue. That is why you use QoS and size WAN links, assuming you are doing toll bypass, correctly.

Hope this helps.

[MJefferson]

We have done several IP Telephony solutions and the PSTN gateways are the least of the quality issues. Most often it is WAN links that are not setup correctly or over subscribed. If the LAN calls are good, the PSTN calls will be good. You might have to tweek the db settings sometimes but more often than not you won't.

[jhelgesg]

Here at Cisco we are using Cisco CallManager & IP Phones almost exclusively, and it works wonderfully. The connection to the PSTN is the easiest and by far the LEAST troublesome connection you'll need to worry about.

Where QoS comes into play most is when you are passing voice traffic over a WAN link for toll bypass or inter-office calling. We use this for our all our remote sales offices. Whenever the same WAN link is passing both voice and data QoS is paramount.

Regards

[pkireev]

We have deployed some voice solutions where we`ve used Cisco 36xx, Cisco AS5300, Cisco 7206 with different digital voice port adapters.

In general it works as it must.