Thursday, August 6, 2015

Troubleshooting A SIP Gateway When Inbound Calls Dont Work

I was putting in a new SIP gateway for a customer to replace an older one.  One thing I came across is that one of the Subscribers (in the Cisco voice cluster) did not have any phone services running.  So I came across this as I was troubleshooting why I could not get a call to come in on the PRI and forward over, via SIP, to the subscriber onsite.  Traces are you best friend, even in the voice world.  Below is how we realized it.  The Subscriber never responds to the gateways invite.


  1. Very cool stuff...thanks. Do you feel that SIP trunks are ready to replace PRI's? I'm still using PRI's everywhere...they are old school, but are rock stable and easy to work with. But I'm getting a lot of vendors pushing SIP to replace my PRI's....less money, very flexible, etc. I do know that the PRI vendors are feeling the pressure, as the cost of my PRI circuits have come way down over the last several years.

    1. Hey Brad. Yeah, PRIs are the most stable for sure. But I always ask people when considering SIP, " When was the last time your internet went out as opposed to your phones?" They will usually say internet has gone out, phones did not. if that is a big deal, I tell them to stay on the PRI. If money is a bigger deal, go with SIP.


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