What is V.35 in the output of "show controllers"?

johnifanx98

When pairing two routers on serial interfaces,

show controllers

shows on one side

V.35 DTE cable

and

V.35 DCE cable

on the other one.

I thought the role of a router is DTE. Then why here one router acts as DTE and other DCE?

spd3432

V.35 is a synchronous data standard. DCE is "data communication equipment" and DTE is "data terminal equipment". For your configuration, if you look at the cable you've got running between the routers, one end should be marked DCE and the other DTE. You need to set the clock speed on the DCE end for communication (data transmittal) to take place.

johnifanx98

spd3432 wrote: »

V.35 is a synchronous data standard. DCE is "data communication equipment" and DTE is "data terminal equipment". For your configuration, if you look at the cable you've got running between the routers, one end should be marked DCE and the other DTE. You need to set the clock speed on the DCE end for communication (data transmittal) to take place.

I thought router/switch will be always DTE equipment, and connections between two routers would be DTE-DTE. Not quite understand why it could be DTE-DCE...

TehToG

You need a device to set the clock frequency.

Typically you won't have a router connected to a router directly. Your router will connect using the DTE - DTE cable to a service providers unit (a CSU/DSU) which will then connect through the providers network. Eventually it might emerge to another sites CSU/DSU where it'll be connected via DTE - DTE to the router again. In this instance the CSU/DSU sets the clock rate.

In a lab we want to cut out the provider so we use this crossover cable (DTE-DCE) but we must set the clock on one side so that the transmit and receiving interfaces are on the same (quite literally) wavelength.