The command is: clock rate 56000
So it will appear on the command line interface as:
Router(config-if)# clock rate 56000
Reference: Networking by Jeffrey Beasley Chapter 6 page 216.
HDLC
The equipment with the "n" designation can transmit data at twice the speed of "g" routers and is more than five times as fast as "b" wireless routers.
It means the data can be transfer serially.i.e ,one by one. So it is less in speed.
Speed... a serial connection can only send one piece of data at a time. Parallel connections have multiple data 'channels' sending data simultaneously 0- which increases the data rate considerably.
Modern networks used two devices for the data packets within the network will flow easily. The two devices are the routers and switches.
routers
it is a communication port which recives and sends data serialy
Parallel data transmission is faster compared to serial data transmission. The speed of a parallel link is equal to the number of bits sent multiplied by the bit rate of each individual path.
A disadvantage of cheap wireless routers would be poor quality of speed because the connection can be interfered with due to other waves surrounding it. Another would be security worries as people within the vicinity could gain access to your private data.
Serial 0/1 is up, line protocol is down
It is used for high speed serial connection data transfer for devices such as camcoders, camera's, etc.
The Ruger web site has sn data if you can get to it.