Netopia Router PN Series - Manual (Page 274)

GL-4 Reference Guide
Unchannelized
The entire T1/E1 line is considered a channel, where:
Ⅲ
The T1 line operates at speeds of 1.536 Mbps and is a
signle channel consisting of 24 T1 time slots.
Ⅲ
The E1 line operates at speeds of 1.984 Mbps and is a
single channel consisting of 20 E1 time slots.
Channelized
The channel is any one of N time slots within a given line,
where:
Ⅲ
The T1 line consists of any one or more channels. Each
channel is any one of 24 time slots. The T1 line operates
at speeds in multiples of multiples of 56/64 Kbps to
1.536 Mbps, with aggregate speed not exceeding 1.536
Mbps.
Ⅲ The E1 line consists of one or more channels. Each
channel is any one of 31 time slots. The E1 line operates
at speeds in multiples of 64 Kbps to 1.984 Mbps, with
aggregate speed not exceeding 1.984 Mbps.
Fractional
The T1/E1 channel is one of the following groupings of
consecutively or nonconsecutively assigned time slots:
Ⅲ
N T/1 time slots (NX56/64Kbps where N=1 to 23 T1 time
slots per Ft1 channel).
Ⅲ
N E1 time slots (NX64Kbps, where N = 1 to 30 time slots
per E1 channel).
Channel Service Unit (CSU): An ancillary device needed to adapt
the V.35 inter face on a Frame Relay DTE to the T1 (or E1) inter face
on a frame relay switch. The T1 (or E1) signal format on the frame
relay switch is not compatible with the V.35 inter face on the DTE:
therefore, a CSU or similar device, placed between the DTE and the
frame relay switch, is needed to per form the required conversion.
CHAP (challenge handshake protocol): A method for ensuring
secure network access and communications.