William C290
Technical User
Hi everyone,
I'm working on a dual SIP trunk setup from our telco (Orange) and using an Avaya SBC (virtualized) in front of Avaya IP Office Server Edition R11.1.
Each SIP trunk is delivered via separate physical links and separate /30 networks:
Since we only have one physical SBC interface (B1) available for SIP trunking, we're trying to handle both links using VLAN separation:
Each VLAN interface is configured with its own IP and default gateway. Routing table on the SBC reflects both networks.
I’d love to hear from anyone who has implemented a similar design or has insight into why this setup might fail despite proper VLAN and routing configurations.
Thanks in advance,
I'm working on a dual SIP trunk setup from our telco (Orange) and using an Avaya SBC (virtualized) in front of Avaya IP Office Server Edition R11.1.
Each SIP trunk is delivered via separate physical links and separate /30 networks:
- Link 1 (Primary): Signaling and media IPs over subnet X.X.X.144/30 (Gateway: X.X.X.145)
- Link 2 (Backup): Signaling and media IPs over subnet X.X.X.36/30 (Gateway: X.X.X.37)
Since we only have one physical SBC interface (B1) available for SIP trunking, we're trying to handle both links using VLAN separation:
- B1.451 → Link 1 (Primary SIP)
- B1.452 → Link 2 (Backup SIP)
Each VLAN interface is configured with its own IP and default gateway. Routing table on the SBC reflects both networks.
- VMware networking is correctly set up with:
- Port groups for both SIP_VLAN451 and SIP_VLAN452
- vSwitch connected to physical NIC (vmnic1)
- Trunking enabled on the switch port
- On the switch:
- Port going to SBC: switchport mode trunk
- Ports going to Orange media converters: switchport mode access + appropriate VLAN (451 or 452)
- Media converters are assumed to not support tagged traffic, so they're on untagged access ports
- SBC cannot reach either SIP gateway via ping from the VLAN interfaces.
- No SIP registration or options exchange is working.
- Direct physical connection to media converter with flat IP works fine, so issue seems to be VLAN-related.
What I need help with:
- Is this design officially supported by Avaya?
(i.e., multiple VLAN-tagged interfaces on same SBC physical port for SIP trunks) - Any known issues with multiple default gateways on different VLANs over the same NIC?
- Does the SBC handle VLAN-tagged traffic differently that would prevent reachability?
- Any detailed guide or best practice design document for SIP trunk load balancing / redundancy over VLANs?
I’d love to hear from anyone who has implemented a similar design or has insight into why this setup might fail despite proper VLAN and routing configurations.
Thanks in advance,