[comp.dcom.sys.cisco] CISCO to X.25 switch connection

david@dit.upm.es (David Fernandez Cambronero) (07/14/90)

Hello,

Here at my University we are trying to connect a CISCO router to a
X.25 switch at a speed of 64kbps. For that we are using the following
hardware: 

* CAMTEC X.25 switch, with an X.21 interface.

* A interface converter, from RS-449/422 to V.35

* CISCO router with a MCI controller and V.35 serial interface.

* Two cables (??) to join the three equipments


The general scheme follows:


      +--------+ X.21 to RS-449 +-----------+    V.35       +-------+
      | Switch |----------------| Converter |---------------| CISCO |
      +--------+                +-----------+               +-------+
         DTE                  DCE            DTE          ??          


My questions are:

1) The CISCO has four possible hardware configurations for the serial
interface:
		- inverted, internal clock
		- non-inverted, internal clock
		- inverted, external clock
		- non-inverted, external clock

Does this mean that the CISCO can behave indifferently as an
electrical DTE or DCE with internal or external clock?

2) We have the possibility of using an internal Tx clock in the X.25
switch. We would like to know which is the best configuration:
	- split clocks 
	- CISCO putting the two clocks, or
	- Switch putting the two clocks
and which cables to use (inverted, direct, etc..)

3) Do you know which V.35 cable must we use two conect two CISCOs between
them?  


I hope not beeing so boring or asking too much but we are very
interested in that connection. Any experiences, ideas or comments will
be very appreciated. 

Thanks in advance,

------------------------------------------------------------------
David Fernandez                 tel: +34 1 5495700,  +34 1 5495762
Dpto. Telematica                      x.367
E.T.S.I. Telecomunicacion            
Ciudad Universitaria            fax: +34 1 2432077
E-28040  MADRID                 tlx: 47430 ETSIT E
SPAIN

E-mail:        dfernandez@dit.upm.es
Alternatives:  dfernandez@goya.uucp
	           dfernandez%dit.upm.es@uunet.uu.net
X.400: C=es; ADMD=; PRMD=iris; O=upm; OU=dit; S=dfernandez;
------------------------------------------------------------------
--
------------------------------------------------------------------
David Fernandez                 tel: +34 1 5495700,  +34 1 5495762
Dpt. Telematica                      x.367
E.T.S.I. Telecomunicacion            
Ciudad Universitaria            fax: +34 1 2432077
E-28040  MADRID                 tlx: 47430 ETSIT E
SPAIN

E-mail:        dfernandez@dit.upm.es
Alternatives:  dfernandez@goya.uucp
	           dfernandez%dit.upm.es@uunet.uu.net
X.400: C=es; ADMD=; PRMD=iris; O=upm; OU=dit; S=dfernandez;
------------------------------------------------------------------