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x.25, XOT and X21 or V35 cables

x.25, XOT and X21 or V35 cables

x.25, XOT and X21 or V35 cables


I need to connect two network x.25 addressable elements. They are miles apart, but we have an IP network between them.
The plan is to connect device A to a Cisco router which will encapsulate the x.25 in TCP/IP (XOT). At the far end of the network the reverse will happen, and the connection will be made to device B using x.25.

At the far end (device B), the physical cable is X21 type.
I'm told that I will need to use the same cable type at the device A end. I would prefer to use V35.

This seems odd to me, and I can't quite believe it is true.
The only thing I can imagine is that something fundamental in the physical attributes of the cable types may constrict the packet size or the timing of signals in some way.

Does anyone know anything about this, or have prior experience?



RE: x.25, XOT and X21 or V35 cables

You need to match cable from router----->to CSU serial port

It could be V.35 or a DB15 cable.  Check modem.  When you order cable it makes a difference to router if it is a DTE or DCE.  Also, make sure if it is Male-Male or Male-Female from router to CSU.  The cables only change if clock leads or held high, and Tx to Rx (Tunrover cable).  Pull spec on Router port and Modem to get this right.

RE: x.25, XOT and X21 or V35 cables

The two cables do not have to be the same type. Be aware that if your "network elements" are SUN servers, you'll have to get a signal converters and connect via the HSI port or card, as I don't think SUN manufactures V.35 or X.21 hardware. HP does have both cards. Or at least they did...

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