RE: FW: RFC 4666 M3UA

Kevin,

1. Regarding how the SGP should respond to the SS7 TFC msg - This question relates only to the behavior of the MTP3
layer within the SGP, and is thus beyond the scope of RFC4666.

2. Regarding the lack of a provision within M3UA to facilitate IP endpoints to send a message to the ITP that would
generate a proper RCT - I agree with you that this is missing from RFC4666. Is this a "must have" issue for you?

Barry Nagelberg

-----Original Message-----
From: Ong, Lyndon [mailto:[email protected]]
Sent: Wednesday, September 12, 2007 3:18 PM
To: Ong, Lyndon; [email protected]
Cc: [email protected]
Subject: RE: [Sigtran] FW: RFC 4666 M3UA

FYI, "ITP" referred to in the email is a type of SG.

From: Ong, Lyndon [mailto:[email protected]]
Sent: Wednesday, September 12, 2007 12:15 PM
To: [email protected]
Cc: [email protected]
Subject: [Sigtran] FW: RFC 4666 M3UA

Forwarding question to the main list for comments.

From: [email protected] [mailto:[email protected]]
Sent: Monday, September 10, 2007 1:50 PM
To: [email protected]; [email protected]; Ong, Lyndon
Subject: RFC 4666 M3UA

Ken,Javier,Lyndon,

I got your names from an inquiry to the IETF about the RFC 4666.
Recently I have been involved in some testing of SS7 congestion and it's reaction from and IP network using M3UA. The
SS7 physical connection utilized two ITP's with BLinks to the SS7 network. It appears the ITP's tested were not capable
of transmitting the RCT ( Route Congestion Test) message in response to the TFC ( Transfer Congestion) they received
with a proper Originating Point Code. The ITP responded to the TFC with a RCT that contained it's own originating point
code. The RCT should contain the OPC of the node at the end of the trunks. This would be the IP endpoint not the ITP.
Further it appears there is no provision within M3UA to facilitate IP endpoints to send a message to the ITP that would
generate a proper RCT.

If possible could you respond to my concerns.

Do I understand the M3UA protocol in the belief there is no workable RCT provision, or is there a provision that would
enable the ITP to reply to a received TFC with a RCT that has the originating point code of the IP endpoint?
I notice the DAUD message contains an Information Parameter. Is there an intent or possibility the DAUD message could
trigger a RCT on the SS7 side of the ITP with the correct OPC of the IP endpoint?

Kevin P. Spence
Verizon Communications
Network Specialist
TSS ENET Essential Network Elements Team
972-615-8199 ext. 4907