6November 1996 3980-A2-GZ40-20
Table 1
(2 of 3)
V.42/MNP/Buffer Configuration Options for SDC
SyncDTE CRC: Ignore
Nxt Ignore CRC16
This configuration option only appears when the Async/Sync Mode configuration option is set to Sync and Sync
Comp Mode configuration option is
not
set to DirectMode.
Synchronous DTE CRC. Determines whether the CRC of the DTE frame is transmitted from modem to modem.
Ignore – No assumption is made about the CRC type. The CRC is transmitted along with the other data in the frame.
CRC16 – The CRC is known to be the 16-bit CRC for HDLC frames defined by ITU-T (generator polynomial x16 +
x12 + x5 + 1). It is removed from the DTE frame by the sending modem and added to the DTE frame by the receiving
modem.
The AT command for SyncDTE CRC is S32=
n
. See Table 4, page 11.
SDC Delay Min: Off
Nxt Off Rx_Clock
This configuration option only appears when the Async/Sync Mode configuration option is set to Sync and Sync
Comp Mode configuration option is
not
set to DirectMode.
Synchronous Data Compression Delay Minimization. Allows the modem to transmit a DTE frame to its DTE in a
discontinuous way to minimize the delay introduced by SDC processing.
Off – The modem does not begin transmitting a frame to its DTE until the entire frame has been received.
Rx_Clock – The modem begins to transmit data from a DTE frame to its DTE even if the end of the DTE frame has not
yet been received by the modem. The receive clock (circuit 115) is clamped when the beginning of a DTE frame has been
transmitted to the DTE and no other data from this DTE frame has been received by the modem. As soon as data from
the current DTE frame can be transmitted to the DTE, the receive clock is released. The Rx_Clock option appears only if
the Tx Clock Source configuration option is set to Internal.
The AT command for SDC Delay Min is #DM
n
. See Table 3, page 9.
Sync Flow Cntrl: None
Nxt None Tx_Clock CTS_SyncDTE
This configuration option only appears when the Async/Sync Mode configuration option is set to Sync and Sync
Comp Mode configuration option is
not
set to DirectMode.
Synchronous Flow Control. Controls the type of synchronous data flow control while using data compression.
None – Modem does not control the flow from the synchronous DTE.
Tx_Clock – The transmit clock (circuit 114) clamps when the modem is unable to accept supplementary data from the
DTE. Tx_Clock appears only if the Tx Clock Source configuration option is set to Internal.
CTS_SyncDTE – CTS signal circuit (106) is set to OFF when the modem is unable to accept supplementary data from
the DTE.
The AT command for Sync Flow Cntrl is #Q
n
. See Table 3, page 9.