Zhone IMACS 8000, Руководство пользователя

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Data Cards 16-7
LDSRU-10P Card LD-SRU Card User Screens and Settings
FRAME
The Frame setting allows you to define the sub-rate format that the port will use and to set the
usable space allotted to each WAN time slot. The choices are DS0A (a) for one subrate time
slot, DS0B with a limit of five subrate time slots (b-5). DS0B framing with a limit of ten
subrate time slots (b-10), and DS0B with a limit of twenty subrate time slots (b-20) are no
longer supported. Figure 16-4 shows the DS0A and DS0B framing subrate time slot
interaction.
Additionally the x.50 option is not supported. nlink (used to transmit clock to related units)
(Note: the RATE and INTF will change when nlink is chosen), and with the SRU-LD*10
(822560) card: adpcm (used to multiplex subrate data on an ADPCM card) and hlink (a
proprietary format used when far end of the circuit has an ADPCM card while the near end
does not).The adpcm frame uses a 24 kbps portion of the ADPCM engine.
RATE
The Rate setting allows you to select the rate in kilobits per second (kbps) for data
transmission. The selection will change depending upon the framing mode and interface
selected. Figure 16-4 shows the bandwidth available for each selection.
The maximum bandwidth of the card depends upon the mode of operations for each port. The
maximum bandwidth for the sync Interface setting is 115.2 kbps and the host will not allow
more than this to be assigned.
The maximum bandwidth for async and v.14 is harder to compute because the computation
depends upon the amount of data being sent.
The async ports have a minimum multiplication factor of 1.2 times a sync port, and v.14 has
a multiplication factor of 1.6 times that of a sync port. Using the Delay Optimization feature
will also degrade the maximum bandwidth by a factor of 1.5 times the maximum bandwidth
figure.
These computation factors suggest a maximum of 96 kbps (96 kbps x 1.2 = 115.2 kbps) for
async ports and 72 kbps (72 kbps x 1.6 = 115.2 kbps) for v.14 ports. However, because of the
nature of async and v.14 data transmission, these limits are not fixed because the user will not
be transmitting data at the full rate. The Delay Optimization feature also degrades the
maximum bandwidth by a factor of 1.5 times the total bandwidth. BERT adds another 2x
multiplication factor to the data rates shown above. These limitations do not apply to the
8000-822560 and 8000-LDSRU-10P LD-SRU cards.