SBC
SBC Manager — SIP Trunk Configuration
SIP trunks define the carriers, PBXs, and peers the SBC exchanges calls with.
Creating a Trunk
Go to Trunks → New Trunk and fill in:
| Field | Description |
|---|---|
| Name | Internal label for this trunk |
| Direction | Inbound, Outbound, or Bidirectional |
| Authentication | IP-based or Username/Password |
| Host | Remote SIP peer hostname or IP address |
| Allowed IPs | Source IP addresses permitted for inbound calls on this trunk |
| Codecs | Ordered list of audio codecs (drag to reorder priority) |
| Max Channels | Maximum simultaneous calls on this trunk (0 = unlimited) |
Click Save to stage the trunk, then go to Apply to push the change to Asterisk. Like all provisioning changes, trunks are staged first and only take effect after an Apply.
Authentication Modes
- IP-based — the SBC accepts SIP for this trunk only from the addresses listed in Allowed IPs (CIDR ranges supported, e.g.,
198.51.100.0/24). This is the standard mode for carrier interconnects; the firewall's SIP allowlist is synchronized from these addresses automatically. - Username/Password — registration/credential-based authentication, used when the peer requires SIP registration or digest auth instead of a static IP relationship.
Editing and Disabling Trunks
From the Trunks list, click any trunk to edit it. To temporarily take a trunk out of service without deleting it, toggle the Enabled switch and apply.
Trunk Health
Monitor → Trunk Health shows the live reachability and status of each configured trunk, so you can confirm a carrier is responding before and after changes.
Related
- Use Carrier Templates for pre-built settings for common carriers (Teams Direct Routing, Twilio, Telnyx, Bandwidth, and more).
- The firewall automatically restricts SIP ports to the IPs of enabled trunks — see the Firewall article.