MTP3 routing overview

 

STP can execute Security and interwork and Message Modification and rate-limit and congestion control and so forth but the most basic and important function is MTP3 routing.

 

 

What is MTP3?

MTP3 layer in SS7 is like the IP layer.

 

OSI 7 Layer vs SS7 layer

 

MTP3 has Routing labels including OPC, DPC and SLS. OPC is like Source IP and DPC is like Destination IP. ANSI and ITU variants are different for length.

 

MTP3 layer stacks from PT

For more detail, please refer to this link.

http://ndl.ru/~hammet/netw/SS7/SS7_Protocol_Architecture_and_Services/sigtran-training/ch07.html

 

 

What is MTP3 Routing?

MTP3 Routing is for STP to send a message to a point you want based on a routing table.

At this time, you can use OPC or DPC or both or other values for routing a message.

 

I will show you DPC based routing. This is the most important routing and basic.

MTP3 Routing on NA2

NA1 sends a message having OPC1111 and DPC5555.

NA2 receives the message. it looks up DPC5555 in Routeset 5555. RS5555 has two routes. Route 3333 has higher Cost 10 than RT 6666 having Cost 20.

NA2 sends it to RT 3333.

 

 

So far so good?