Zhone 3810Plus Guia do Utilizador Página 199
- Página / 217
- Índice
- RESOLUÇÃO DE PROBLEMAS
- MARCADORES
Avaliado. / 5. Com base em avaliações de clientes
I-13980-A2-GB30-40 October 1998
Synchronous Data Compression
Overview
The Paradyne proprietary Synchronous Data
Compression (SDC) feature allows an increase of
throughput in data transmission, and has an error
correcting procedure so that transmitted data is less
sensitive to channel disturbances.
The ITU-T recommendations V.42bis and V.42 have
data compression and error correcting (EC) procedures
for DCEs connected to asynchronous DTEs. These
procedures form the basis of Paradyne’s SDC feature.
With the SDC feature, two DTEs can exchange data
via a synchronous protocol while the DCE provides the
new synchronous data compression and error correction
functions. The synchronous data from the local DTE,
after compression, is inserted into DCE frames which are
sent to the remote DCE. Inverse operations then occur at
the remote DCE.
SDC can be used with V.34 and V.32 family
modulations on dial or leased lines, and in a dial backup
or standby mode.
Synchronous Data Format
The SDC feature supports the High-level Data Link
Control (HDLC) and Synchronous Data Link Control
(SDLC) type protocols for synchronous DTE data. An
HDLC frame is composed of an information field
containing the data to transmit, plus an overhead
(address, control, and FCS fields) used by the DTE
protocol. Flags opening and closing the HDLC frame
serve as frame delimiters.
A 3800Plus modem with the SDC feature supports
DTE frame sizes up to 4300 bytes. This conforms to the
X.25 recommendation which defines a maximum size of
data packets as equal to 4096 bytes.
If the modem has the SDC Delay Min configuration
option set to Rx_Clock, there is no limitation on the
DTE frame size for the DTE frames transmitted from the
remote modem to this local modem, since the whole
frame need not be buffered.
The SyncDTE CRC configuration option determines
whether the CRC of the DTE frame (the FCS field) is
transmitted. If the CRC type is known to be the 16-bit
CRC for HDLC frames as defined by ITU-T (generator
polynomial x
16
+ x
12
+ x
5
+ 1), the CRC can be removed
by the local modem and added to the DTE frame by the
remote modem.
SDC Algorithm
The compression algorithm is based on V.42bis
British Telecom Lempel ZIV (BLTZ).
DTE and DCE Frames
Data exchanged between the local and remote DCEs
is according to the LAPM protocol. The structure of a
LAPM frame (DCE frame) is identical to the HDLC
frame. The data from the DTE is compressed into the
information field of the DCE frame. After compression,
one DTE frame is segmented into one or several DCE
frames.
Data Synchronization
Data exchanged between the synchronous DTE and
the modem is synchronized by two clock signals. Data
coming from the DTE is synchronized by the transmit
clock and data received by the DTE is synchronized by
the receive clock. The transmit clock is provided by the
modem on circuit 114 or by the synchronous DTE on
circuit 113. The receive clock is provided by the modem
on circuit 115.
When the transmit clock is provided by the modem,
the transmit and receive clocks are locked on the same
clock source internal to the modem. In this
configuration, the user can select rates on the DTE-DCE
line (or clock frequencies) in the range from 1.2 kHz to
128 kHz.
I
- COMSPHERE 1
- Important Safety Instructions 3
- United States 4
- Government Requirements 5
- D3980-A2-GB30-40 October 1998 5
- Table of Contents 7
- 12. Fax Operation 9
- Appendices 9
- COMSPHERE 3800Plus Modems 10
- List of Figures 11
- List of Tables 12
- Objectives and Reader 13
- Assumptions 13
- How to Use This Manual 13
- Related Documents 14
- Introduction 15
- COMSPHERE Models 16
- SDC Feature 16
- Optional ETC Feature 16
- Installation 17
- Modem Installation 18
- DTE Connection 19
- Network Management 21
- System Connection 21
- Modem Power-Up 21
- Removing and Replacing 22
- Modem Installation 24
- 3811Plus Installation 25
- Front Panel Operation 27
- SDU12345678910111213141516 28
- Table 4-1 29
- DCP LEDs 29
- Label Color Indicates 29
- Hidden Choice Indicators 30
- Right Scroll Indicator 30
- Menu Structure 32
- Top-Level Menu Status and 33
- Operational Messages 33
- Table 4-3 34
- Top Level Menu Status 34
- Using AT Commands 37
- Using the Diagnostic 38
- Control Panel (DCP) 38
- Call Setup Branch 41
- Table 5-1 46
- Valid Dial Command Modifier 46
- Status Branch 47
- Test Branch 53
- 494-13079-02 62
- 494-13080-02 63
- Configuration Tables 67
- Table 8-1 69
- (3 of 7) 69
- # Stop Bits: 1 69
- DTR Action: Ignore 69
- (4 of 7) 70
- DSR Control: Forced_On 70
- (5 of 7) 71
- RTS Action: Ignore 71
- CTS Control: Forced_On 71
- (6 of 7) 72
- RTS/CTS Delay: 0 msec 72
- LSD Control: Stndrd_RS232 72
- DTE Dialer 74
- Table 8-2 78
- (5 of 5) 78
- *AT Cmnd Mode: Normal 78
- DTR Cont Repeat: Disable 78
- Line Dialer 79
- Table 8-3 83
- DTR Auto Redial: Dir 1 83
- MI/MIC Dialing: Disable 83
- Dial Line 84
- Table 8-4 85
- (2 of 4) 85
- Automode: Enable 85
- Autorate: Enable 85
- (4 of 4) 87
- Proactive Retrain: Enable 87
- FallFwdDelay: Disable 87
- Leased Line 88
- Table 8-5 89
- (2 of 5) 89
- *LeasedLine Rate: 33600(V34) 89
- *Autorate: Enable 89
- Asymmetric Rate: Enable 92
- *FallFwdDelay: Disable 92
- V.42/MNP/Buffer 93
- Configure Branch 101
- Table 8-7 102
- (2 of 2) 102
- Test Configuration Options 102
- V54 Address: Disable 102
- V54 Device Type: Peripheral 102
- Security Configuration 106
- Control Branch 109
- AT Command Equivalent 110
- Clone To Remote 112
- To Local via DTE 114
- Remote Branch 115
- Security 119
- VF-Side Passwords 120
- Command Set and S-Registers 121
- DTE-Side Passwords 121
- Combination of VF-Side and 121
- Administrative Password 122
- EditPasswdTable 123
- Select Index 123
- Set Answer Sec 126
- Set Orig Sec 127
- Reset Security 128
- Database Table Examples 130
- Fax Operation 133
- AT Command Set and 135
- S-Registers 135
- Any-Key Abort 136
- Table 13-1 138
- (2 of 15) 138
- AT Commands 138
- (3 of 15) 139
- (4 of 15) 140
- (6 of 15) 142
- (7 of 15) 143
- (8 of 15) 144
- (9 of 15) 145
- (10 of 15) 146
- (13 of 15) 149
- (15 of 15) 151
- S-Register List 152
- Table 13-2 153
- S-Registers 153
- (5 of 15) 156
- (11 of 15) 162
- (12 of 15) 163
- (14 of 15) 165
- Menu Tree 167
- Result Codes 171
- Table B-1 172
- (2 of 3) 172
- (3 of 3) 173
- Troubleshooting 175
- Table C-3 177
- Modem – VF Connection 177
- Symptom Action 177
- 3810Plus Installation 178
- Technical Specifications 179
- Table D-1 180
- Specifications Criteria 180
- Pin Assignments 183
- EIA-232-D Pin Assignments 184
- VF Connector Pin 185
- Assignments 185
- JM8 to RJ11 Crossover Cable 186
- Configure Branch 187
- Call Response 188
- Call Answer Commands 188
- Valid (VAL) 189
- Invalid (INV) 189
- Default Configuration Options 191
- Equipment List 197
- Synchronous Data Compression 199
- Flow Control Method 200
- SDC Negotiation 200
- Monitoring SDC Performance 200
- Tuning SDC Efficiency 202
- Glossary 203
- 00282600 217
Manuais e produtos relacionados com Modems Zhone 3810Plus
Modems Zhone 3921Plus Manual do Utilizador
(29 páginas)
(29 páginas)
Panasonic SA-EUR7622X20 Handbücher
Bedienungsanleitungen und Benutzerhandbücher für Audio Panasonic SA-EUR7622X20.
Wir stellen 1 PDF-Handbücher Panasonic SA-EUR7622X20 zum kostenlosen herunterladen nach Dokumenttypen zur Verfügung Bedienungsanleitung
Comentários a estes Manuais