ELSA LANCOM Business 6000, Руководство пользователя

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Connection via 2-Mbit interface
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ELSA LANCOM Business 6000
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44
EN
Each timeslot was given a defined data width of 8 bits; 8000 data packets
(frames) are transferred per second and timeslot. This results in the required
bandwidth per timeslot of
8 bits/frame x 8000 frames/second = 64 kbps
The 2-Mbit bandwidth of G.703 is thus broken down into 32 timeslots of 64
kbps each. The timeslots are numbered from 0–31.
Reservation of timeslots for control data
The first of these 32 timeslots (0) is permanently reserved by G.704 for the
transmission of framing data. A number of terminal devices, certain terminal
adapters for example, also permanently reserve timeslot 0 for the
transmission of control data. These reserved timeslots thus perform tasks
very comparable to those of the ISDN D channel. All non-reserved timeslots
are available for the transmission of user data. In their function and
bandwidth, they correspond to the B channels in the ISDN.
As a rule, any combination of timeslots can be used for the user and control
data, only timeslot 0 is reserved for G.704 framing information. Intermediate
exchanges always treat timeslots 1–31 as user data. The distribution of these
31 timeslots for user data and supplementary control data is determined
solely by the configuration of the terminal equipment. Normally, there would
be no reason to reserve one of the 31 timeslots for the transmission of
supplementary control data in fixed, point-to-point connections.
Free coupling of timeslots
In G.704, timeslots can be optionally coupled for greater bandwidth. The
coupling is set in the terminal devices. The coupled timeslots result in
connection channels with the appropriate bandwidth. These connection
channels can also be used for fixed connections to a variety of remote
stations.