Some time ago I wrote about a free SIP service from sip-ua.com (you can check out the post here). I had been using the free service fairly regularly to test in my lab, but the inbound auto attendant took more time to use than I would like. When you work on an IVR application and make test calls rapidly over a short period of time it becomes trying to wait 3 for a prompt just to listen to a playback timing change that may only take 1.5 seconds to verify.
Needless to say, I went in search of something that better suited what I doing; enter flowroute. Flowroute had 2 big advantages for me, the first of which was price. Since I am just using the service for my lab I needed something that had a very low monthly fee and no usage minimum, and flowroute checked both those boxes. The second big factor for me was the availability of a proxy/registrar server because my internet connection unfortunately does not have a static IP address and the last thing on my mind is trying to troubleshoot routing settings every time my IP changes.
Getting the flowroute SIP service to work with a CUBE (Cisco Unified Border Element), which is Cisco’s implementation of Session Border Controller on an ISR (Integrated Services Router), is fairly straight forward; just an inbound and outbound dial-peer along with the SIP-UA credentials. You can find my working config from my 2811 below.
voice service voip allow-connections sip to sip ! dial-peer voice 1 voip incoming called-number . dtmf-relay rtp-nte no vad ! dial-peer voice 2 voip destination-pattern <your DID from flowroute> session protocol sipv2 session target ipv4:<ip of your inside device> dtmf-relay rtp-nte ! sip-ua credentials username <username> password <password> realm sip.flowroute.com authentication username <username> password <password> realm sip.flowroute.com no remote-party-id retry invite 2 retry register 5 timers connect 100 registrar dns:sip.flowroute.com expires 3600 !