The SBC Core transports SIP signaling over UDP, TCP, TLS and SCTP. Acceptable transport types for Ingress SIP signaling are specified on the SIP signaling port and on the SIP trunk group. The transport types used for Egress SIP signaling are specified by the SBC in its routing response, determined by the SBC on a SIP trunk basis, or queried from an external DNS server.

The SBC supports defining independent media port ranges on a per-trunk group basis (SIP, H.323 and GW) and at the system level using the configuration object mediaPortRange. When configuring a mediaPortRange for a Trunk Group, the UDP port range is defined using baseUdpPort and maxUdpPort objects.

The system reserves two UDP ports for each incoming UDP media call leg: one for (S)RTP and one for (S)RTCP. Thus, a configured port range must contain at least twice as many port numbers as the maximum simultaneous calls to be supported for that IP Trunk Group.

The following two parameters are used to define the UPD port range for mediaPortRange object:

  • baseUdpPort – The starting (base) port number for the range of UDP ports to use for RTP/RTCP media (inclusive). This value must be within the system-wide media port range. The baseUdpPort range is 1024-65534, or "none" (the default value which indicates SBC does not apply this SIP trunk group control, and instead uses the mediaPortRange specified by system-wide settings).

  • maxUdpPort – The maximum UDP port number for the range of UDP ports to use for RTP/RTCP media (inclusive). This value must be greater than the baseUdpPort and within the system-wide media port range. The maxUdpPort range is 1024-65534, or "none" (the default value which indicates SBC does not apply this SIP trunk group control, and instead uses the mediaPortRange specified by system-wide settings.


NOTE: When provisioning a UDP media port range, set the range slightly larger than the actual number of ports needed to support maximum simultaneous calls.

Each trunk group can include an mediaIpAddress to indicate which IP address to use when allocating UDP media. The default value is 0.0.0.0 indicating that the system will function as it currently does by choosing an IP Address from the mediaIpInterfaceGroup. The mediaIpAddress can be configured as either an IPv4 or IPv6 address except for H323, which does not support IPv6 addresses. Any IP address configured must belong to the IP Interface Group configured as the mediaIpInterfaceGroup for the trunk group.

Use the CLI 'show table' command to view the ipInterfaceGroup table listing UDP (or TCP) port ranges marked (mediaPortRangeAssigned) or unmarked (mediaPortRangeUnassigned) for the indicated IP Interface Group.

For configuration details, refer to:

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