- This topic has 15 replies, 1 voice, and was last updated 14 years, 10 months ago by rala.
11th December 2007 at 08:46 #49983FahimGuest
can anyone tell me about N7 – how many A channels can it handle at a time or how many subscribers at a time be accomodated with one N711th December 2007 at 12:57 #49984PixGuest
In theory, one N7 channel can take care of 256 A=interface channels (256 subscribers).
In reality, you must use a big safety margin to avoid any type of congestion (can only use up to 40% of capacity). Therefore, the rule is :
1 N7 for 100 A channels (100 calls)
Easy to remember, isn’t it ?
Rule of thumb : 4 PCM (max. 120 calls) for 1 N712th December 2007 at 05:29 #49985FahimGuest
your answer has been of great help to me12th December 2007 at 09:20 #49986FahimGuest
I would like to put another question regarding N7 – that is SCCP – what is it’s role and how it works in the context of A channel ?12th December 2007 at 15:57 #49987pixGuest
N7/SCCP carries all signalling messages that can be exchanged between BSC and MSC (CONNECTION REQUEST, HO REQUIRED, ASSIGNMENT REQUEST, RELEASED, AUTHENTICATION, CIPHERING, etc…). It also carries SMS (am I correct ?? i remember this…) 🙂
All other timeslots carry data or voice.12th December 2007 at 17:47 #49988FahimGuest
In normal cases N7 is defined in the 16th TS of the first Ater TP of one Ater Mux – that means SCCP should be available on those TPs only, right ? if so – then why the busy/available SCCP column of USD A-interface seems rather a bit indiscriminate in nature ?12th December 2007 at 18:04 #49989pixGuest
i’m not familiar with the USD window, and the terms you use. But maybe what i’m going to tell you will answer your question :
when a comm is located on a certain AterMux, it doen’t mean the signalling will go through the SS7 which is n the same Ater Mux.
Even more complicated : Most of the time, for one communication, the signalling BSC-MSC is on one SS7 TS, and the signalling MSC-BSC is on another S7 TS 🙂
It’s totally dynamic and “random”.13th December 2007 at 03:34 #49990SohagGuest
Can you explain what is th eactual meaning of 2*2-34+2 which we find ericsson MMU fron panel.13th December 2007 at 08:45 #49991FahimGuest
I think you are talking about MW PDH links. think that is wirtten in product documents of MINILINK of Ericsson19th December 2007 at 09:18 #49992FahimGuest
But – does sccp works on a TS or A channels where N7 has not been defined ? say, ss7 has been defined in one A out of four in one ATR – so other As – will SCCP work in other As?19th December 2007 at 20:52 #49993pixGuest
SCCP and SS7, it’s the “same” thing (one is the name of the protocol, the other the name of the pysical channel)
the SS7 of 1 TS out of 4 E1 will carry enough signalling for the 4 E1’s.
If you have 8 E1s, you’ll need two SS7. The signalling of one circuit channel will be carried on either SS7, not necessarily the one located on its “4-E1s” group.
Is that answering your question ?9th January 2008 at 09:18 #49994ralaGuest
I think the busy/available SCCP column of USD A-interface is showing “the function of DTC board”(You can see from the configuration table).
In USD, the one that has busy/available SCCP mean this DTC board has BSSAP/SCCP function.
For the others has N7/MTP and TCHRM function depend on the BSC configuration.
Warmest regards,13th January 2008 at 07:20 #49995FahimGuest
Here lies the confusion – the DTCC board whose corresponding Ater TP contains the N7 – does not always carry SCCP rather it seems quite random in nature -if I am right !! can you please elaborate your answer regarding this ?17th January 2008 at 02:34 #49996ralaGuest
The DTC (SBL) are identified according to the software provided and because of the different software loading in the DTCC (RIT) so there are three types of DTCC:17th January 2008 at 03:09 #49997ralaGuest
The BSSAP/SCCP DTC manages the user application layer messages and user connections(SCCP)–> In USD, we will see the SCCP available at this DTC type.
The N7/MTP DTC manages the MTP–> the DTC that contains the N7 on timeslot 16.
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