- This topic has 15 replies, 1 voice, and was last updated 16 years, 8 months ago by Rect.
29th May 2004 at 12:47 #38285Ashish GoelGuest
I have read at many places regarding & lnk overload. It should be ideally between .2 to .4 Er i.e. load should not go beyond 40%. can anyone explain why?
Also what will happen if an IAM has been sent and the A side is sending the SAM or it is receiving the CRG or ACM message and during this the link breaks down? will the call be immediately released or the messages will be exchanged on a redundant link.
Ashish29th May 2004 at 17:57 #38286S.VijayGuest
If there is a Live Redundant Link….the Messages will be passed through others.
This is done by MTP Layers through Network Management.Study MTP L2&L3 You can understand.
If all the Link goes down..still the messages can be passed….if you have STP Routing.All done by MTP.
Rgds2nd June 2004 at 12:37 #38287HariGuest
Between two point codes, there will be a linkset maintained by MTP3. Link set involves multiple links ( max 16).
It is expected that the link resource consumption should not cross-40% because in case of other link failure, one link needs to handle the left-over load, like that if there are 8-links which are down, the left 8 links will have resource-comsumption of 80%, even in this scenario the connectivity will be stable with out major issues ( like conjuction etc).
Hope this helps………..
Hari3rd June 2004 at 06:22 #38288Ashish GoelGuest
In this case will the message sequencing be affected during link break up and what will happen to running calls? i have come to know that the running the running calls will be released since there are some mesages exchanged b/w switches which maintain the cic and tell each other which call is running on which cic. whats your view.
Also can you tell me how the status of the trunks for ex. whether they are blocked from A side/B side or there is a hardware failure at either end due to which the ckts are blocked is maintained by switch.
Ashish3rd June 2004 at 06:59 #38289HariGuest
MTP-3 will make sure to send the messages which are not acked by the peer in case of link-break down, in the sequence requested by the peer. This is one among the primary goals of SS7.
If you search for change-over ( COO/COA/CBD/CBA) you will come to know more about MTP3 retransmission mecahnism.
-Hope this helps………
Hari3rd June 2004 at 11:25 #38290S.VijayGuest
Better read on MTP Layers and C7 Network Management by MTP3.
Th links are managed by MTP Layers.While CIC Informations goes through USER PART Layer-Upper Layer.
So ISUP Layer wont care about how MTP Transports the Message it gives the SIF to MTP which can send the message in a available SL or If you Have ATM/IP(New Trends ) as Physical Links MTP sends through them.
Rgds8th June 2004 at 17:44 #38291Charles TGuest
Am a switching (GSM) engineer working on Siemens D900. I have a problem with C7 signaling with my international gateway. They have an NEC NEAX-61E switch. They are always complaining that my C7 links are causing ‘overload’ in their switch. The message they get on the terminal during this phase is ‘C7LINK FAILURE CP03-CCSC03, EXCESSIVE DELAY OF ACK.(NORMAL)’. Is there anyone with NEC backgroup to help intepret this msg as the guys at the other switch seem to have no clue?8th June 2004 at 17:44 #38292Charles TGuest
Am a switching (GSM) engineer working on Siemens D900. I have a problem with C7 signaling with my international gateway. They have an NEC NEAX-61E switch. They are always complaining that my C7 links are causing ‘overload’ in their switch. The message they get on the terminal during this phase is ‘C7LINK FAILURE CP03-CCSC03, EXCESSIVE DELAY OF ACK.(NORMAL)’. Is there anyone with NEC backgroup to help intepret this msg as the guys at the other switch seem to have no clue?14th June 2004 at 13:09 #38293Kiran MattaGuest
This is regarding your 2nd point.
1. If there is redundent link configured. The messages will be transfered in the redundent link.
2. In casae there is no redundent link. in case of SAM or CPG you need to start timers monitor them. In general some stacks will automatically start timers for the same. if the timer expires it will send REL (on both sides) to ur application and to the network.
Thanks and Regards,16th June 2004 at 18:02 #38294S.VijayGuest
Check the TIMERS at both End.
I think your swithch is trying again again with some process ..like ACM/REL.for which NEC doesnt response properly.
put a ANALYZER and monitor what happens exactly.
And check the C7&ISUP Parameters at both ends.May be ISUP Version may create problem.
Rgds21st June 2004 at 10:20 #38295manuelGuest
is there anyone of you have a manual of NEAX commands. please send me. my email address is email@example.com June 2004 at 07:51 #38296Charles TGuest
Thanks S.Vijay for the reply. I verified that I am using White Book ISUP and the NEC switch is usuing Blue Book. I have fallen back to Blue Book. Problem seems to have gone away but I will get C7 traces on protocol analyzer and will let you know. Thanks again for that eye-opening reply!!!23rd June 2004 at 08:41 #38297S.VijayGuest
Nice to hear that yuo have sorted out the Problem.
Rgds24th June 2004 at 08:48 #38298Charles TGuest
Thanks Vijay. I did a C7 trace on the link and saw strange phenomena. Every ISUP msg from the MEC switch comes repeatedly like 4 to 6 times continuosly in a space of 1 second or less. Send me your e-mail and I will mail you a sample trace.
Thanks again.24th June 2004 at 11:46 #38299S.VijayGuest
Hi Charles…Send me C7 Traces for both Directions.
And mention me the Analyzer You are using.