01-23-2003 07:38 PM - edited 03-02-2019 04:29 AM
Hi all,
To confirm the serial ports of two routers are working, I am connecting them back to back by two V35 cables(V35 male & V35 female), and I know one router should be DCE and whilst the other should be DTE. Here are my questions are:
1) How can I make this test work? I've heard there are DTE & DCE cables, then how can I identify a DTE or DCE cable? By the female or male connector on the cable itself or some other methods?
2) Where should I enable clocking? On the DCE side or DTE side?
I've tried different combinations of above two but with no luck, can u guys shed me some light on this?
TIA,
Goku
01-23-2003 08:21 PM
Here are some answers:
1) Yes, physically by the male and female connector.
Also, you can identify a DTE or DCE cable through
a label on the cable itself (if they have).
I think its like a white sticker with a "DTE" or "DCE" label.
From your router, you can also use
"show controllers serial" to determine if the cable
connected to the serial port is a DTE or DCE.
2) Clocking is on the DCE side.
Assuming that Router1 uses the DTE cable:
[Router1]
interface serial 0
ip address ***** *****
no shutdown
[Router2]
interface serial 0
ip address ***** *****
clock rate
no shutdown
Hope this helps.
01-24-2003 12:00 AM
Thanks for your reply a.manosca .
I think my current male & female cables are both DTE type as the outputs of "show controller serial 0" are:
" DTE V.35 clocks stopped"
Therefore does that mean both male or female V35 cables can be DCE and cables are only identifed by plugging to a router serial port if there is no sign of DTE or DCE marked on the cables..
Thks again,
Goku
01-24-2003 01:00 AM
You mentioned this on your first post:
"By the female or male connector on the cable itself or some other methods?"
So I assumed you have identified the male (with "exposed" pins) as the DTE
and a female (with "holes") as the DCE.
If you typed the "show controller serial 0" on the TWO routers,
you should look for an output something like:
Router# show controllers serial
MK5 unit 0, NIM slot 1, NIM type code 7, NIM version 1
idb = 0x6150, driver structure at 0x34A878, regaddr = 0x8100300
IB at 0x6045500: mode=0x0108, local_addr=0, remote_addr=0
N1=1524, N2=1, scaler=100, T1=1000, T3=2000, TP=1
buffer size 1524
DTE V.35 serial cable attached
Based on experience, I haven't seen a MALE V.35 cable used as a DCE.
Why? Because the V.35 DTE cable is used to connect to a DCE device,
typically a Modem. I don't know how this sounds but you can say:
"Male (DTE) cables have sticks and female (DCE) cables have holes".
These links should help:
I hope I made it quite clear.
Regards.
01-24-2003 01:55 AM
Thanks for your information clearing up the cable conventions, from my observations i guess there may be an issue with the DCE(male) cable as it never shows any sign of DCE when attached to the two routers, therefore I will get another DCE cable to verify.
WIth thanks & regards,
Goku
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