Spectrum Business SIP trunk
Spectrum delivers its SIP trunk (over coax or fiber) through a Spectrum-managed gateway installed on your local network. That gateway terminates the carrier side and talks plain SIP to Exovo over the LAN — so unlike an internet trunk there is no registration and no username or password: both sides authenticate each other by IP address. The Exovo template is built for exactly that.
What you need from Spectrum
- The LAN IP address of the Spectrum gateway — the only value the trunk needs.
- Your DIDs, and confirmation that Spectrum has the PBX's LAN IP and destination SIP port. For LAN mode, give Spectrum 5082 and the Host IP Address shown under Admin → Connectivity → Network. Existing trunks with LAN mode disabled may still use 5080; coordinate changing the destination port with Spectrum before switching modes. An IP-authenticated Spectrum trunk should not send calls to 5060, which requires credentials.
Add the trunk
Admin → Trunks → Add trunk, choose United States → Spectrum Business (SIP Trunk), and enter the gateway's LAN IP as the host. Leave the credentials empty — they aren't used. Exovo creates the trunk with registration off (the list shows IP auth instead of a registration state — that's normal), UDP transport, no SRTP, video disabled, the PBX in the media path, the Diversion header on for forwarded calls, and PCMU as the only codec: the Spectrum gateway refuses calls that offer anything else first, which is the single most common reason a Spectrum trunk "connects but won't place calls".
Enable LAN mode
On the trunk's Options tab, select Use the configured LAN address for this SIP peer and save. Set Admin → Connectivity → Network → Host IP Address to the PBX's LAN IPv4 address. Keep the public-IP setting available for internet providers; the Spectrum trunk advertises the LAN address independently.
Spectrum's gateway must send inbound calls to the PBX LAN address on 5082 for this mode. The registrar port on the Exovo trunk remains the port the Spectrum gateway listens on, commonly 5060. See LAN trunks and gateways for the port distinction, migration from 5080 and complete testing steps.
Allow the gateway's IP
Inbound calls arrive from the gateway's LAN IP, so add it under Admin → Security → IP Blacklist → Trunk allow-list. When every trunk on the system is a known-IP carrier like this one, turn on Restrict inbound to trunk IPs there too — SIP from anywhere else is then rejected outright. See IP blacklist and allow-list.
Inbound DIDs
Add your DIDs to the trunk's DID Numbers tab in international format (+1XXXXXXXXXX) and
build inbound rules for them as usual; until then, calls land on
the trunk's default route.
Testing
- Outbound: dial a mobile from any extension. If the call fails immediately, check the trunk's codec list on the trunk page — it must read PCMU only.
- Inbound: call one of your DIDs. If it does not ring, check that Spectrum is sending to the configured PBX LAN address on 5082 for LAN mode (5080 for a legacy trunk with LAN mode off), and that its gateway IP is on the trunk allow-list. Spectrum delivers the dialed number as 10 digits; that's fine — DIDs match on the number's tail, so a DID entered as +1XXXXXXXXXX still routes.
- Firewall: nothing needs to be forwarded for this trunk — the gateway is on your LAN. Keep 5060 closed at the edge as the installation guide says.