MTP2:Architecture

A MTP2 Link must be associated with one Trunk instance. It’s a 1 to 1 association. MTP Level 2 defines the functions and procedures of the signaling system for providing reliable transfer of signaling messages over a signaling link.

Important note: It is important to ensure that the received and transmitted clock of the Trunk was synchronized. This can be useful to remove undesirable FIB and BSN error. See section “Clock Configurations” in the TB640 user’s guide.

Priorities

No pre-emption of data occurs in the process of being transmitted or requiring retransmission. Only a single congestion priority is supported for ANSI and ITU. For a TTC/NTT link, transmitted data buffers are prioritized based on the priority indicated by MTP Level 3.

Flow control

The MTP Level 2 software regulates data flow when resource utilization (such as buffer pool size or queue length) reaches specifies thresholds. For each threshold, MTP Level 2 performs one of the following actions:

• Informs the layer manager about flow control.
• Sends a link status signal unit with status "B" (busy).
• Sends a flow control indication to the upper layer.

The MTP Level 2 software prevents deadlocks and overload conditions from occurring.