Почему происходит разрыв связи?

[Максим]

Modem type: IDC-5614BXL/VR+ (Plus) Firmware revision: V2.23

Time Online.................. 00:01:30
Termination Reason........... INCOMPATIBLE PROTOCOL
Tx Rate (Last/Init/Min/Max).. 26400/26400/26400/26400 bps
Rx Rate (Last/Init/Min/Max).. 28800/28800/28800/28800 bps
Modulation................... V.34
Protocol/Compression......... LAP-M (SREJ)/V.42bis
Line Quality................. 46
Tx/Power Drop/Rx Level....... 10/0/28
SNR Last/Min/Max............. 29/29/29
Highest Rx/Tx State.......... 67/67
EQM Sum...................... 004C
RBS Pattern.................. NA
Rate Drop.................... NA
Digital Loss................. None
Retrains Issued/Granted/Auto. 0/0/0
Renegs Issued/Granted........ 0/0
FForwards/FBacks/Denied...... 0/0/0
Forced FB/FB after FF/MaxREJ. 0/0/0
Last dialed number........... PXXXXXXX
Flex fail


Symbol Rate.................. 3429
Carrier Frequency Hz, Rx/Tx.. 1959/1959
EQM Value (Last/Min/Max)..... 46/16/92
EQM Hits..................... 0
EQM Last 10 Readings......... 22 24 22 19 18 19 20 22 19 19
Last Retrain/Reneg Status.... None
Last Retrain/Reneg Reason.... None
Last Retrain/Reneg Time...... 1 minutes ago
Handshake Time/Retries....... 25 seconds/0
Non-linear Encoding, Rx/Tx... ON/ON
Precoding, Rx/Tx............. ON/OFF
Shaping, Rx/Tx............... ON/OFF
Trellis Encoding, Tx......... 16 state
Pre-Emphasis Index, Tx....... 10
Band Edges Lower/Upper, Hz... 150/3825
Round trip delay, ms......... 5,2
Last Rx/Tx State............. 67/67
Energy at 3750Hz/Average .... 322/696
Detection of 120 Hz Tones.... No
Detection of Dual PCM........ Yes
V.8 Negotiation Started...... Yes
V.8bis Success............... No
V.8bis CRe,CRd,CL,MS,ACK,NAK. No/No/No/No/No/No
Remote supports Symbol Rates. 2743 2800 3429 3000(L) 3000(H)
Remote supports Symbol Rates. 3200(L) 3200(H) 3429(Tx)
Remote supports Power Drop... Yes
Remote is CME Modem.......... No
Remote supports V.34bis...... No
Remote Max SR Difference..... 0 Symbol Rate Steps
Remote Frequency Source...... Internal
Error Correction Status Byte. ADP:R ODP:T
Error Correction Status Byte. SYNC UA:R SAMBE:T XID:T XID:R
Frames REJected, Last/Total.. 1/0
Frames Errors, Rx/Tx......... 0/0 (0,0%/0,0%)
Frames Count, Rx/Tx.......... 665/219
Error Control Frame Size..... V.42 LAPM (128)
Error Control Timeouts....... 1
Error Control Link NAKs...... 0
Compression Dictionary Size.. V.42bis (2048)
Characters Received.......... 51724
Characters Sent.............. 5861
Average CPS, Rx/Tx........... 574/65
Characters Lost, Rx/Tx....... 0/0
Estimated Noise Level, -dBm.. 57


Modem type: IDC-5614BXL/VR+ (Plus) Firmware revision: V2.23

Time Online.................. 00:00:50
Termination Reason........... INCOMPATIBLE PROTOCOL
Tx Rate (Last/Init/Min/Max).. 28800/28800/28800/28800 bps
Rx Rate (Last/Init/Min/Max).. 28800/28800/28800/28800 bps
Modulation................... V.34
Protocol/Compression......... LAP-M (SREJ)/V.42bis
Line Quality................. 19
Tx/Power Drop/Rx Level....... 10/0/28
SNR Last/Min/Max............. 27/27/27
Highest Rx/Tx State.......... 67/67
EQM Sum...................... 0034
RBS Pattern.................. NA
Rate Drop.................... NA
Digital Loss................. None
Retrains Issued/Granted/Auto. 0/0/0
Renegs Issued/Granted........ 0/0
FForwards/FBacks/Denied...... 0/0/0
Forced FB/FB after FF/MaxREJ. 0/0/0
Last dialed number........... PXXXXXXX
Flex fail


Symbol Rate.................. 3429
Carrier Frequency Hz, Rx/Tx.. 1959/1959
EQM Value (Last/Min/Max)..... 19/15/23
EQM Hits..................... 0
EQM Last 10 Readings......... 17 15 19 18 18 17 17 17 17 17
Last Retrain/Reneg Status.... None
Last Retrain/Reneg Reason.... None
Last Retrain/Reneg Time...... 0 minutes ago
Handshake Time/Retries....... 24 seconds/0
Non-linear Encoding, Rx/Tx... ON/ON
Precoding, Rx/Tx............. ON/OFF
Shaping, Rx/Tx............... ON/OFF
Trellis Encoding, Tx......... 16 state
Pre-Emphasis Index, Tx....... 10
Band Edges Lower/Upper, Hz... 188/3825
Round trip delay, ms......... 4,6
Last Rx/Tx State............. 67/67
Energy at 3750Hz/Average .... 321/693
Detection of 120 Hz Tones.... No
Detection of Dual PCM........ Yes
V.8 Negotiation Started...... Yes
V.8bis Success............... No
V.8bis CRe,CRd,CL,MS,ACK,NAK. No/No/No/No/No/No
Remote supports Symbol Rates. 2743 2800 3429 3000(L) 3000(H)
Remote supports Symbol Rates. 3200(L) 3200(H) 3429(Tx)
Remote supports Power Drop... Yes
Remote is CME Modem.......... No
Remote supports V.34bis...... No
Remote Max SR Difference..... 0 Symbol Rate Steps
Remote Frequency Source...... Internal
Error Correction Status Byte. ADP:R ODP:T
Error Correction Status Byte. SYNC UA:R SAMBE:T XID:T XID:R
Frames REJected, Last/Total.. 1/0
Frames Errors, Rx/Tx......... 0/0 (0,0%/0,0%)
Frames Count, Rx/Tx.......... 1075/283
Error Control Frame Size..... V.42 LAPM (128)
Error Control Timeouts....... 11
Error Control Link NAKs...... 0
Compression Dictionary Size.. V.42bis (2048)
Characters Received.......... 100695
Characters Sent.............. 8568
Average CPS, Rx/Tx........... 2013/171
Characters Lost, Rx/Tx....... 0/0
Estimated Noise Level, -dBm.. 55



--------------------------------------------------------
Modem type: IDC-5614BXL/VR+ (Plus) Firmware revision: V2.23

Time Online.................. 00:08:57
Termination Reason........... INCOMPATIBLE PROTOCOL
Tx Rate (Last/Init/Min/Max).. 26400/26400/19200/26400 bps
Rx Rate (Last/Init/Min/Max).. 28800/28800/28800/28800 bps
Modulation................... V.34
Protocol/Compression......... LAP-M (SREJ)/V.42bis
Line Quality................. 25
Tx/Power Drop/Rx Level....... 10/0/28
SNR Last/Min/Max............. 29/29/29
Highest Rx/Tx State.......... 85/87
EQM Sum...................... 0036
RBS Pattern.................. NA
Rate Drop.................... NA
Digital Loss................. None
Retrains Issued/Granted/Auto. 0/0/0
Renegs Issued/Granted........ 0/2
FForwards/FBacks/Denied...... 0/0/0
Forced FB/FB after FF/MaxREJ. 0/0/1
Last dialed number........... PXXXXXXX
Flex fail


Symbol Rate.................. 3429
Carrier Frequency Hz, Rx/Tx.. 1959/1959
EQM Value (Last/Min/Max)..... 25/16/114
EQM Hits..................... 0
EQM Last 10 Readings......... 25 25 25 25 29 30 26 26 26 27
Last Retrain/Reneg Status.... Remote Rate Renegotiation
Last Retrain/Reneg Reason.... Remote Rate Renegotiation
Last Retrain/Reneg Time...... 5 minutes ago
Handshake Time/Retries....... 24 seconds/0
Non-linear Encoding, Rx/Tx... ON/ON
Precoding, Rx/Tx............. ON/OFF
Shaping, Rx/Tx............... ON/OFF
Trellis Encoding, Tx......... 16 state
Pre-Emphasis Index, Tx....... 10
Band Edges Lower/Upper, Hz... 188/3825
Round trip delay, ms......... 6,4
Last Rx/Tx State............. 67/87
Energy at 3750Hz/Average .... 332/653
Detection of 120 Hz Tones.... No
Detection of Dual PCM........ Yes
V.8 Negotiation Started...... Yes
V.8bis Success............... No
V.8bis CRe,CRd,CL,MS,ACK,NAK. No/No/No/No/No/No
Remote supports Symbol Rates. 2743 2800 3429 3000(L) 3000(H)
Remote supports Symbol Rates. 3200(L) 3200(H) 3429(Tx)
Remote supports Power Drop... Yes
Remote is CME Modem.......... No
Remote supports V.34bis...... No
Remote Max SR Difference..... 0 Symbol Rate Steps
Remote Frequency Source...... Internal
Error Correction Status Byte. ADP:R ODP:T
Error Correction Status Byte. SYNC UA:R SAMBE:T XID:T XID:R
Frames REJected, Last/Total.. 1/1
Frames Errors, Rx/Tx......... 1/0 (0,0%/0,0%)
Frames Count, Rx/Tx.......... 4040/949
Error Control Frame Size..... V.42 LAPM (128)
Error Control Timeouts....... 13
Error Control Link NAKs...... 0
Compression Dictionary Size.. V.42bis (2048)
Characters Received.......... 223498
Characters Sent.............. 22574
Average CPS, Rx/Tx........... 416/42
Characters Lost, Rx/Tx....... 0/0
Estimated Noise Level, -dBm.. 57

Строка инициализации: S91=10\N2S202.7=1M4E0+A8E=,,,0

[Technical Support]

По видимому, проблема связана с работой механизма Selective Reject. В некоторых модемах он реализован некорректно. Иногда возникают ситуации, когда кадр данных, отвергнутый с помощью SREJ, вообще не удаётся протолкнуть. При использовании обычного механизма (REJ) модемы имеют возможность перейти на меньший размер кадра и перепослать данные. В случае SREJ такая ситуация приводит к разрыву связи.

Если у Вас такая ситуация возникает часто - откажитесь от SREJ.
_________________
Inpro
Technical Support