How to prevent SS7 node to send traffic

Hi team,

I have a question about how to prevent SS7 node to send traffic to other SS7 node if this other node cant deliver the messages into final destination. Detail topology, config, and question are described in the attachment. Would you please provide assistance and answer?

thank you in advance

[admin]

I think that if you route on basis of DPC than messages will automaically stop taking the path via STP1 as the signalling route of HLR1 via the STP1 will appear down at MSC1 and like you said this isn't the case in case of routing on GT!

May be someone else can give better options!

Originally Posted by admin

I think that if you route on basis of DPC than messages will automaically stop taking the path via STP1 as the signalling route of HLR1 via the STP1 will appear down at MSC1 and like you said this isn't the case in case of routing on GT!

May be someone else can give better options!

Correct, this is not the case of DPC routing, but GT routing. Just to add more info:
1. MSC 1 connection to STP 1 and 2 use Network Indicator 2
2. STP 1 / 2 connection to STP 3 / 4 use Network Indicator 3
3. STP 3 / 4 connection to HLR 1 use Network Indicator 2
4. STP 1 connection to STP 2 uses Network Indicator 2
5. STP 3 connection to STP 4 uses Network Indicator 2
6. MSC 1, STP 1, and STP 2 are owned by Operator A
7. HLR 1, STP 3, and STP 4 are ownded by Operator B

I havent got the answer whether there is automatic mechanism to prevent MSC 1 to send traffic to CdPA 987654321 (HLR 1) via STP 1 if STP 1 connection to STP 3 and 4 are down.

If anyone does have the answer or have some comment/feedback, please do share it here.

if u turn off the routes on STP1 to reach STP 3 and 4, MSC1 will only route the GT address u are using trough STP2

Hi vmarines,

From MSC1 point of view, CdPA 987654321 is routed to STP 1. As long as ss7 links between MSC 1 and STP 1 are up, then MSC1 keeps sending traffic to STP 1 (although STP 1 cant route it further). Is there any solution?

I don't think STP1 has a way to prevent MSC1 from sending traffic to it.
b/m would work in my view:

1. MSC1 will always route traffic to STP1.
2. Primary route from STP1(for HLR GT) should be towards the DPC of STP3 or 4.
3. Secondary route from STP1(for HLR GT) should be towards DPC of STP2.

so if primary route towards STP3 or 4 is down, secondary route towards STP2 will become active.

Hi JDK,

Well, as you said, there's no mechanism for STP1 to alert/inform MSC1 to keep sending traffic for CdPA 987654321 when STP1 cant process it further to the next hop. I guess everyone agrees on it and we can call it "limitation" of SS7?

For your idea (second route to STP2), I guess it will depends on specific STP vendor, since you will do first route on NI=3, and second route on NI=2. I dont know whether STP can do this.

Yes you are right. This will depend on specific STP vendor.
Do let me know if you get to know the solution