13
H
ANDSHAKING
,
ERROR
CONTROL
,
DATA
COMPRESSION
,
AND
THROUGHPUT
This chapter contains information about:
■
Handshaking
■
Selective Reject
■
V.90 Capabilities
■
Error Control
■
Data compression
■
Getting maximum throughput
Handshaking
With each call, Courier V.Everything modems go through a link
negotiation process with the remote device. Another name for the
negotiation process is "handshaking.
Courier V.Everything modems default to V.90 modulation and try for the
highest possible speed when they attempt to connect with another
modem: 56 Kbps. If the remote device is not V.34-capable, a connection
is made using the highest compatible modulation scheme (x2, V.34, V.FC,
V.32
terbo
, V.32
bis
, and so on, down to as low as Bell 103, or 300 bps).
Selective Reject
The Courier V.Everything modem supports Selective Reject for analogue
calls. Selective Reject improves performance on noisy lines by reducing
the amount of overhead incurred when the protocol must resend data
due to errors
When Selective Reject is active, only the frame that contained the error is
resent, instead of the frame plus all of the following unacknowledge
frames.
Summary of Contents for Courier
Page 12: ......
Page 28: ...1 14 CHAPTER 1 CONNECTING TO YOUR ISP ...
Page 36: ...3 4 CHAPTER 3 UPGRADING YOUR MODEM ...
Page 58: ...6 6 CHAPTER 6 WORKING WITH MEMORY ...
Page 64: ...8 4 CHAPTER 8 CONTROLLING EIA 232 SIGNALING ...
Page 72: ...9 8 CHAPTER 9 ACCESSING AND CONFIGURING THE COURIER V EVERYTHING MODEM REMOTELY ...
Page 80: ...10 8 CHAPTER 10 CONTROLLING DATA RATES ...
Page 96: ...12 6 CHAPTER 12 FLOW CONTROL ...
Page 108: ...13 12 CHAPTER 13 HANDSHAKING ERROR CONTROL DATA COMPRESSION AND THROUGHPUT ...
Page 112: ...14 4 CHAPTER 14 DISPLAYING QUERYING AND HELP SCREENS ...
Page 122: ...15 10 CHAPTER 15 TESTING THE CONNECTION ...
Page 142: ...17 8 CHAPTER 17 TROUBLESHOOTING ...
Page 156: ...A 14 APPENDIX A S REGISTERS ...
Page 172: ...B 16 APPENDIX B ALPHABETIC COMMAND SUMMARY ...
Page 178: ...C 6 APPENDIX C FLOW CONTROL TEMPLATE ...
Page 186: ...E 4 APPENDIX E V 25 BIS REFERENCE ...