Cisco 3600 Router Question

[iotone]

is there a difference in setting the clock rates on the DCT vs. on the DCE?? I was trying to simulate a slow link between the two, and I kept setting the clock rates on the DCT and not the DCE, which is contrary to some instructions that I had.

Can any Cisco gurus enlighten me on the effect of setting the clock rate on the DCT (and whether it really does simulate a slow link)??

 

[Cscutch]

The clockrate is always set on the DCE equipment. And the other equipment DTE not DCT gets its clockrate from the DCE.

Chris

 

[spidey07]

Originally posted by: Cscutch
The clockrate is always set on the DCE equipment. And the other equipment DTE not DCT gets its clockrate from the DCE.

Chris

bingo.

DTE = data terminal equipment, meaning you get your clock from the other guy (DCE)

 

[randal]

On that note, anybody ever had the weird situation where the LEC was providing clock in the middle of a T1 loop? Just the other day I was setting up a T1 and couldn't get anything to work until I set both dsu/csus to line clock. If I set it up with the standard internal/line clocking (one on each end) 'twas a no go. Incredibly, Qwest assures me there is no clock on the line.

bah, it's Qwest, what do I expect.

randal

 

[spidey07]

Originally posted by: randal
On that note, anybody ever had the weird situation where the LEC was providing clock in the middle of a T1 loop? Just the other day I was setting up a T1 and couldn't get anything to work until I set both dsu/csus to line clock. If I set it up with the standard internal/line clocking (one on each end) 'twas a no go. Incredibly, Qwest assures me there is no clock on the line.

bah, it's Qwest, what do I expect.

randal

that's the norm - lec providing clocks.

the DACs provides the clock on both ends from a master. remember, you're working off of a mux, which means it provides clock.

 

[iotone]

thanks for the info... strange enough, i'm trying to set the clock rate to 1,000,000 but it keeps taking down the serial interface... any ideas on why this could be happening?

edit: for clarification, when i set the clock rate to anything lower than 125,000 everything stays up fine, but after that i see messages saying that the interface is taken down... i even provide 'no shutdown' after setting the clock rate...

 

[randal]

are you using v.35 or something else? I know that rs-232 tops out around 128,000.

http://www.cisco.com/univercd/cc/td/doc...lticon/3810soft/cmdref/uioref.htm#3068

"Be aware that the fastest speeds might not work if your cable is too long, and that speeds faster than 148,000 bits per second are too fast for EIA/TIA-232 signaling. It is recommended that you only use the synchronous serial EIA/TIA-232 signal at speeds up to 64,000 bits per second. To permit a faster speed, use EIA/TIA-449 or V.35."

 

[iotone]

ah ic... if i recall correctly, i saw v.28, so that maybe the cause there??

in any case, thanks for everyone's help, should be done playing with the routers after tonite