serial cable

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Hi,
If you have two routers with db60 serial,
and you put a v.35 dce cable in one, and a v.35 dte cable in the other,
do you then just connect the two v.35 connectors together,
or do you have to put something in between them (like something that
makes the whole thing a "null" cable ?

dik



Re: serial cable
Richard Sole wrote:

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Yup. remember to config the router with the DCE cable to povide clocks.
--
Paul Matthews                          
paul@cattytown.me.uk
http://www.hepcats.co.uk

Re: serial cable
If you have one cable to connect routers back-to-back, you don't have to put
anything between. One router, where you have DCE end of cable connected,
should provide clocking for the serial link. If you not sure, which end is
which, check the output of the "show controller serial X/X" command on both
routers. One end should say DTE, and another DCE. Then issue "clock rate
XXXXX" on the DCE end.

Good luck,

Mike
------
Cisco IP Phone Headset Adapters
www.headsetadapter.com



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Re: serial cable
Thanks...
the reason I dont want a single (crossover) cable, as the one you refer to,
is
that I see it as a learning exercise (I am doing CCNA), and I was opting for
the
more "realistic" option, with real cables that could (but won't) be plugged
into some real DCE.
So you just plug the two V.35 ends together (I am assuming one is male
and one is female), is that correct ?
(I haven't bought any cables yet)

dik

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Re: serial cable
Thanks,
I have one follow-up question:
When, in your lab, you connect a DTE and a DCE cable together, does it
matter what cables you use, e.g. will two X.21 or two EIA/TIA-449 (or 232)
or two EIA-530 work just as well as the two V.35, and will you have to
configure differently depending on which you use ?  I believe the 232 is
asynchronous, presumably you will have to set something to "async" in IOS ?

dik

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Re: serial cable
Hi,

Simple put... different serial cables give you possibly different "speeds".
e.g. With a V.24 you could have 768Kbps synch while with a V.35 you could
have 8Mbps synch.

You can even use the console cable to interconnect two routers using AUX
ports ( up to 128Kbps )

Regards,
Gabriele

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Re: serial cable
Richard,

In "real life" you never configure DTE/DCE modems. In most cases you have
preconfigured unit, you connect to the router by DB-60 V.35 cable. Or, with
new network modules, you just plug RJ-48 (same size as RJ-45 cable) into
your router. So, connecting routers back-to-back by DTE-DCE cable or by T1
cross-over cable IS a "real life" unless you work for ISP as Telco
technician.

Theoretically, if you want to spend an extra couple hundreds dollars, you
can get DTE/DCE modems, but all you will get is a couple "black boxes" to
simulate exactly the same scenario as you have with single back-to-back
cable. Plus, for CCNA, CCNP or even CCIE, it does not matter, *how*
physically devices are connected. The matter is that devices ARE connected.

Good luck,

Mike
------
Cisco IP Phone Headset Adapters
www.ciscoheadsetadapter.com


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Re: serial cable
Thanks for a very useful reply.  I wasn't sure how much I should get into
the "look and feel" of various connectors, but I suppose talking about them
here gives a better perspective than just reading the book.
On your advice, I will just get whatever is the cheapest on the day.

dik

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Re: serial cable


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Re: serial cable
hi,
    from my understanding of routers i am going to state the obvious,
just in case u havent tried it. u know that at default serial
interfaces are shutdown. you will first have to bring the interfaces up
on both routers. then configure the dce router  with a clock rate of
56000. b4 this u must give each interface an ip address.
ping the other router if youget a reply then your connection is good .i
hope i have been of help
Richard Sole wrote:
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