According to the Spark documentation, we should be able to make calls from any public SIP system to our Spark SIP address, i.e. email@example.com
However, when trying to make a call in this way, I just get "hostname not found". If I try and perform an nslookup on me.call.ciscospark.com there are no DNS records publically available.
We have the full Spark full service with Webex, Care & Pro Pack etc so it shouldn't be a license poroblem.
Can anyone advise how third parties can call my Spark SIP URI direct from their own SIP system?
In this case, a SRV record is used. The SRV record used would be _sips._tcp.<domain>.call.ciscospark.com.
Thanks. I checked and can see the DNS record:
priority = 5
weight = 10
port = 5061
svr hostname = l2sip-cfa-01.wbx2.com
But how does a normal SIP endpoint (external to Cisco) know about this? I.e. If I have a phone registered to an Asterisk server, or some third-party SIP standard endpoint, calling firstname.lastname@example.org doesn't establish the call...
Try this for some more info, SIP SRV is spart of the SIP std. see link below for some more info..
In a standards based video environment, the infrastructure goes through and queries the DNS SRV records pertaining to SIP/H323 to find the destination and route the call as needed. One of the SRV records that is queried is what I mentioned above. In your case, I dont think the Asterisk will do this kind of queries since its a voice endpoint (although I am not an Asterisk expert). If you have a standards based video endpoint like Cisco, Polycom, Lifesize, I would suggest to give it a try and it "should" work.
For some extra reading, refer to the RFC which explains this in detail.
Thanks very much, I'll check out what Asterisk supports along with any other SIP endpoints.