SIP trunks

[Mattmayn]

I have a customer that wants to use SIP trunks to get some of their dial tone, does anyone have any suggestions?

[ralph]

We have SIP trunks working in our office.   We're using Bandwidth.com.
These are not our primary lines but they've worked fine with no issues once setup.
I have sucussfully used Faxes and Modems across the trunks.

Setting them up was a bit of a challange for our network engineers.   Something strange was happening to the IP routing.  Just took them a while to trace down.

Ralph

[MitelMania]

im using SIP trunks in my Lab from vitelity.net over the standard internet and can be shaky in high traffic times.

my customers successfully using SIP trunks have MPLS installed in their sites and that their SIP provider

my lab trunks work as good as SIP trunks on the Internet ever will.... remember the internet as a whole does not support QoS throughout...  and also your customer will want to make sure that at least their Pipe and maybe their ISP do support QoS on their portion of the network...

SIP trunks uncompressed take 100k bandwidth cost PER concurrent call...

make sure you set up your COR so that fax machines going through the PBX dial out over standard PSTN trunks...(at least until t.38 really works)

-Christopher

[ralph]

I know this isn't Mitel related but since we're discussing SIP here I thought I'd share this one.
We have a customer using a Cisco Express and SIP trunks.
Customer was having trouble with calls coming in from certain cell phone providers.   
The problem turned out to be the callerl ID.   
If the caller ID had a comma (,) in it i.e. Lastname, first name, the call would fail.
The resolution was to downgrade the software in the Cisco.  Fauld was with the lastest version.

Ralph