On Tue, Jun 12, 2001 at 10:42:28AM +0200, Jeroen Verstegen wrote:

Thanks Karsten for the tip.

Cabling was indeed changed, as another system moved to antoher location. Have you got a tip as to how to check if the right cables are used in the right place? It is very difficult to distinguise between them.

Yes it's easy. male female 3 RX+ 2a --[100 Ohm]----+ ---------- / ---------- 4 TX+ 1a --[100 Ohm]--+ | | 87654321 | | 12345678 | 5 TX- 1b -------------+ | |__ __|/ |/_ /_| 6 RX- 2b ---------------+ |____| |/___| NTBA: 2b 2a 1b 1a This are the official numbering of the S0 bus. As you can see on normal S0 are only the 4 middle pins of a 8 pin RJ45 are used, one pair is 4/5 for TX (from NTBA to TE) and one 3/6 for RX. It is important that all TE connect 3 to 3 4 to 4 5 to 5 6 to 6. If a cable is wrong (cross 4/5 for example) it seems to work, but only one TE at the same time. if you put the two plugs of the cable side by side, the colors of the wires should match. Unfortonatly new RJ54 cables use color stripes instead of full colored so it maybe difficult to see it, but a simple pass trough tester (a battery and a lamp) can help. cable cable ---------- / ---------- / | 87654321 | | 87654321 | |__ __|/ |__ __|/ |____| |____| -- Karsten Keil SuSE Labs ISDN development