Stream Control Transmission Protocol (SCTP) is a transport layer protocol similar to TCP, but is characterized as message-oriented protocol transporting a sequence of messages (each being a group of bytes) rather than an unbroken stream of bytes (TCP behavior). In SCTP, a sender sends a message in one operation, and that exact message is passed to the receiving application process in one operation.
The SCTP as a Transport preference and SCTP retransmission timer are configured from the SIP Trunk Group. The SCTP as a transport protocol and SCTP profile are configured in the SIP signaling port. The SCTP Profile CLI syntax is described below.
The SCTP Profile Parameters are as shown below:
Name of SCTP profile.
The SCTP Heartbeat Interval in seconds. (default = 4)
SCTP Idle Timeout Interval in seconds. (default = 3600)
The number of Inbound Streams for this SCTP profile. (default = 1)
The SCTP Max INIT retry. (default = 8)
Enable flag to use ordered delivery in SCTP.
The number of Outbound Streams for this SCTP profile.
The SCTP Path MTU in bytes. (default = 1500)
The number of Peer Transport Addresses for this SCTP profile. (default = 1)
The Maximum retransmissions per SCTP association. (default = 0)
The number of Retransmissions per path for this SCTP profile. (default = 8)
The SCTP RTO Initial in milliseconds. (default = 50)
The SCTP RTO Max in milliseconds. (default = 200)
The SCTP RTO Min in milliseconds. (default = 40)
Set flag to enable SACK Delay in SCTP.
In this example, the following steps are accomplished:
- Create SCTP profile named "SCTP02" with following configuration: outboundStreams - 2, inboundStreams - 2, peerTransportAddress - 2, retransmissionsPerPath - 8, hearbeatInterval - 6, orderedDelivery - enabled, retransmissionPerAssociatioon - 1, rtoInitial - 100, rtoMax - 200, rtoMin - 50.
- Configure SCTP as a transport protocol in SIP signaling port, and SCTP profile "SCTP02" is associated with the particular zone.
- Configure SCTP as a Transport preference and SCTP retransmission timer to 50 seconds in the SIP Trunk Group.
- Configure SCTP as a transport protocol in IP Signaling Profile.