SIP Troubleshooting Checklists

SIP Connection Information

Property Value in EU-Production Value in EU-Staging Value in US-Production
Inbound SIP-Proxy sip.cognitivevoice.io sip.demo.join-us.cloud sip.atl.join-us.cloud
Inbound SIP-Proxy IP 145.14.231.149 145.14.231.171 204.124.15.179
Inbound SIP-Proxy Port 5060/UDP (plain),
5060/TCP (plain),
5061/TCP (TLS)		 5060/UDP (plain),
5060/TCP (plain),
5061/TCP (TLS)		 5060/UDP (plain),
5060/TCP (plain),
5061/TCP (TLS)
Outbound SIP-Proxy IP 145.14.231.153 145.14.231.175 204.124.15.183
RTP Port-Range
(inclusive)		 Start: 50000/UDP
End: 57999/UDP		 Start: 50000/UDP
End: 57999/UDP		 Start: 25000/UDP
End: 64999/UDP

General Notes

  • No whitelisting is necessary in CVG, any valid SIP communication is accepted and appropriate responses are sent out.

OPTIONS

  • The CVG SIP proxies will generally answer to SIP OPTIONS ping.

  • Use a sensible User-Agent header because pings from commonly known scanner utilities will not be answered.

  • SIP OPTIONS pings must be properly addressed to the CVG endpoint. E.g. the Request-URI must refer to our inbound proxy, e.g. OPTIONS sip:sip.cognitivevoice.io ...

INVITE

  • Call destinations must be international phone numbers with a leading country code in either +49... or 0049... formats. Other formats or amounts of leading zeros may lead to call rejection.

  • The request URI must refer to our inbound proxy, e.g.: INVITE sip:+4944444444@sip.cognitivevoice.io. Using the IP address and optionally an explicit SIP port (5060 or 5061 for TLS) is also fine.

  • The SIP URI in the From header must never refer to any of our SIP proxies. E.g. From: Someone <sip:+4944444444@sip.cognitivevoice.io> would not be valid since this would identify the user as a local user.

  • If no Privacy header is sent, then SIP addresses in the From header will be considered anonymous/supressed, if the display name is anonymous, the user-port of the URI is anonymous or the host ends with .invalid. All checks are done case-insensitive.

REFER

  • CVG does not accept REFER requests, however it is possible to REFER calls to CVG and it is possible to send out REFER requests from CVG using the /call/refer API.

Encryption

  • Make sure the SIP communication works without encryption before enabling it!

  • TLS/SIP in combination with SRTP-SDES is supported using modern TLS 1.2 and TLS 1.3 cipher suites (this is usually used from contact center solutions).

  • TLS/WSS in combination with SRTP-DTLS is supported using modern TLS 1.2 and TLS 1.3 cipher suites (this is usually used for WebRTC).

  • Support for specific cipher suites can be probed using the curl command line tool via the URL https://sip.cognitivevoice.io:5061.

Audio

  • Advertised Codecs are: G.722, OPUS, G.711a and G.711u (prioritized in this order)