Re: E1Definition

[Lawrence Mashungwa <lawm at 4site.bw>]

At 02:44 PM 07/10/2000 +0900, Brian Candler wrote:
>On Sun, Jul 09, 2000 at 01:52:14PM +0000, Adiel AKPLOGAN wrote:
>> Let put out what i need. I whant to know exatly how E1 link work and what 
>> communication standard are used on it. The thing is that i got some E1 (by 
>> Radio) link from the local Telecom. The are talking me about C.7 
>> communications standard (protocol). As i will use these E1 for digital 
>> dialup acces with a CISCO AS3500, i will need to know exactly what that
C.7 
>> is! As i know tha the Quad E1/PRI Interface i will use support G.703
protocol.
>
Brian has explained the theory quite well, I will just do quick recipe.

This is based on Ericsson AXE-10 switch (Popular in Southern Africa)

A. the physical side (transmission) Confirm with the Telco..
Line Coding   a. AMI or HDB3  ( in Botswana they use HDB3)
TS16 CAS Multiframe (I assume CAS instead of S7)  yes or no
Frame Type:  G704 (crc checking) or G732 (no crc checking)
This will get the line working btwn you and your telco

B. R2 signalling..
Is R2 siganlling digital or Analog..Hopefully they are modern and its digital
If analog -( you are alone)
Set line supervsion to CAS
set ABCD idle states (for voice comms)
typical they are:	Mask 	1100  (most implementations only use AB)
			Idle	1001
			Seize	0001
			Szack	1101  (seize acknowledge)
			Answer 0101  (confirm this one diffrent in most areas)
Now for MFC:(R2 register settings) (MFC - MultiFrequency)
			Clear forward		1001 time out 150 
			Clear Backward	1101    "     150
			Blocking		1101	   "   200

With the above you will have timeslot-1 for framing and ts16 for signalling
leaving
you with 30 channels/ports...

Now set your NAS to use those physicall ports!!
PLEASE get your telco guys to confirm the above settings for and also check
the line
as follows: Use a CN3000 (or similar) protocol analyser for R2 at following
points:
1.from switch to trxm
2.from trxm to trxm end
3.from trxm end to your premise
4.after your NTU (normally provided by telco eg Newbridge 2902)

And also check if your NAS has coax (75ohm) or 120-ohm (RJ45 like)
sometimes for 120ohm the cables they provide have wrong parity, check those..

hope this helps


	
Lawrence Mashungwa            |^^^|
Technical Director(4Site) ====($ $)====
Tel:  +267 581714              ($)	Cell: +267 72141414
email: lawm at 4site.bw			Url:   www.4site.bw

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