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 your PBX's LAN IP and port 5080 as the SIP destination on the gateway (Spectrum configures this side; give them the IP shown on Admin → Connectivity → Network as the Host IP Address). The port matters: 5080 is Exovo's trunk port. Port 5060 is the phone port — it demands a password on every call, so a gateway sent there gets every inbound call rejected while outbound still works.
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".
Allow the gateway's IP
Inbound calls arrive from the gateway's LAN IP, so add it under Admin → Advanced → 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. No ring means Spectrum is sending to port 5060 instead of 5080 (the most common cause — outbound works, every inbound call fails), the gateway's IP isn't on the trunk allow-list, or Spectrum has the wrong PBX IP on their side. 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.