Setting up SIP Link requires a complex series of integrations. Use this article to help troubleshoot during the integration process.
Before you begin
To troubleshoot SIP Link, make sure you have:
- Packet Capture on your SBC
- Packet Capture on your Firewall
- A tool to view packet captures
- Access to your SBC logs
Note: If you need additional help with troubleshooting, contact your SBC vendor or carrier.
Confirm signal connection with SIP Link
Signaling for SIP Link uses Transport Layer Security (TLS). TLS consists of a package of certificates created by public Certificate Authorities (CA). You can check the status of your TLS connection from the admin control panel SIP Link landing page.
- Confirm your TLS certificate is from one the following CAs:
- DigiCert
- Entrust DataCard
- GlobalSign
- GoDaddy
- Sectigo
- Start a 3-way Transmission Control Protocol (TCP) handshake, followed by a TLS handshake.
When the certificates exchange, Voice sends a certificate followed by the SBC’s certificates.
- Once this exchange takes place, application data can be exchanged between Voice and your SBC.
Troubleshoot call quality
If you’re having issues with call quality, make sure your network latency is consistent and low. Call quality is at its best when Voice traffic takes the shortest path between Voice and the SBC. Your goal should be a round-trip latency of 100 ms or less.
To test network latency:
- Ping the Voice media front-end server from the SBC’s external interface.
- Remain connected to Voice for at least 4 hours.
- Make sure your latency is consistent and 100 ms or less. Don’t average the latency value and check for occasional latency spikes.
- If your latency is not 100 ms or less, use the traceroute utility to print the network path from your SBC or client machine to the Voice media front-end. The path should be as short as possible, for example:
- For desktop, use > traceroute lens.voice.google.com
- For Chromebooks, use > tracepath lens.voice.google.com
- For SBCs, use traceroute siplink.telephony.goog or traceroute lens.voice.google.com
Troubleshoot common signal connection issues
Troubleshoot common media connection issues
Before you begin troubleshooting your media connection, make sure your network satisfies the following conditions:
- Your network is using Datagram Transport Layer Security (DTLS) or Session Description Protocol Security Description for Media Streams (SDES) encryption, but not both.
- You’re not using unencrypted SDP offers. Calls made this way are automatically terminated.
- MKI or Crypto Lifetime must are disabled.
- If using DTLS, it’s using a self-signed cert on the SBC. The cert does not need to be a CA signed cert.
- Ensure that one of the supported codecs are configured in the Voice profile of your SBC, G711 mulaw (PCMU), G711 alaw (PCMA), Opus, or G722.
- Dual tone multi-frequency (DTMF) is present as telephony events.
- Assign a dedicated Public IP to your SBC’s external interface.
- Configure the Source and Destination NAT for your firewall.
Related topics
Google, Google Workspace, and related marks and logos are trademarks of Google LLC. All other company and product names are trademarks of the companies with which they are associated.
