Router!
Talking about, the measurement of the clock rate, so it is been supplied by the CSU/DSU!
But, just stating the above the statement would not complete the answer, has been a reader… I feel I should also be knowing what exactly CSU/DSU are!
Channel Service Unit/Data Service Unit:
It is a hardware device about the size of an external modem that is been used for the conversion of a digital data frame from the communication technology which is been used over a LAN in the frame of WAN and vice versa.
So letting you all understand via an example, If you own a business that, you function from your home and for that you have taken up a digital line on lease to a Telephone Company or a gateway at an ISP, now you see that you have two different CSU/DSU, one at the end of gateway host and other at the end of Telephone Company.
The CSU transmit and receive signals to and from WAN line, which bars the electrical interface from either side of the unit. The CSU has a functionality that can echo a loopback signals from the Telephone Company for the processes of Testing whereas, the DSU takes the control of the line and functions in converting input and output between RS-449, RS-232C and V.xx frames from the time-division multiplexed (TDM) DSX frames on the T-1 line and the LAN. The DSU has the control over the signal regeneration and timing errors also it provides an interface equivalent to modem between the CSU and Data Terminal Equipment (DTE).
CSU/DSUs are made as discrete items or are now and then part of a T-1 WAN card. A CSU/DSU's Data Terminal Equipment interface is generally good with the V.xx and RS-232C or comparative serial interface. Makers of a particular unit or incorporated CSU/DSUs incorporate Adtran, Cisco, and Memotec.
The CSU started at AT&T as an interface to their nonswitched advanced information framework. The DSU gives an interface to the Data Terminal Equipment (DTE) utilizing a standard (EIA/CCITT) interface. It likewise gives testing abilities.
Hope this would have cleared all your doubts..!
Cheers!
