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New Member

leased line


what is the meaning for the term like...

DCD=up DSR=up DTR=up RTS=up CTS=up

this appears when u say the command

#sh int serail0



Re: leased line

RTS - Request to Send

DSR - Data Set Ready

DCD - Received Line Signal Detector

CTS - Clear to Send

DTR - Data Terminal Ready

These handshaking signals are similar to the ones you have on serial com port communication between PCs.

New Member

Re: leased line

can you please explain the significance of these


Re: leased line

For example, RTS, CTS are used for hardware flowcontrol.

Devices are of two types, DTE and DCE device. DCE devices are typically switches, hubs etc, while router are usually DTE type interface. So the DCE can use CTS to slow down the rate of DTE.

New Member

Re: leased line

One of my router shows ...

DCD=up DSR=up DTR=down RTS=down CTS=up

This router is connected to a Modem.

What does this mean now


New Member

Re: leased line

Now it shows that the CTS=down..

I can ping the remote router , but there are lot of errors in link


Cisco Employee

Re: leased line


Please find some info below

Clear To Send (CTS) pin 5

The CTS is an input signal. This means that it waits for a signal of the connected device.

When the connected device receives the RTS-signal and it opened to receive data, it returns a signal back. This is the CTS-signal for the initial computer

This link also may help you

New Member

Re: leased line

RTS Request To Send DTE output, DTE would like to transmit

CTS Clear To Send DTE input, DCE is ready to transmit

DSR Data Set Ready DTE input, DCE is ready to communicate

DCD Data Carrier Detect DTE input, data link established, also known as Receive Line Signal Detect (RLSD)

DTR Data Terminal Ready DTE output, device ready

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