Обновил вчера вечером прошивку для ADSL2, поставил самую последнюю. Вроде, раньше не замечал, но сёдня сутра глянул на график статистики e-mule-я и увидел, что соединение рвётся через равные промежутки времени, примерно 25 минут, и примерно через минуту всё работает снова.
При этом я не знаю падает ли соединение только с интернетом, или модем вообще перезагружается, сорри, вечером посмотрю и покажу лог.

Может кто сталкивался с такой проблемой? как это можно вылечить?

Попробуйте поставить модуляцию ADSL (Multi-mode). Мне помогло
Если не поможет , то давайте статистику (SNR Margin/Line Attenuation/Data Rate)

Multi-Mode как раз и стоит, по умолчанию.

ADSL Firmware Version: 4.03.03.00 - 3.02.00.03 - 3.02.06.00 Annex A - 01.07.02 - 0.49
ADSL Software Version: V2.01B01T01.RU.20060522
Line State Connected
Modulation Multi-mode
Annex Mode ANNEX_A
Max Tx Power -38 dBm/Hz

SNR Margin: 10 8 dB (Downstream, Upstream)
Line Attenuation: 17 9 dB (Downstream, Upstream)
Data Rate: 5882 766 kbps (Downstream, Upstream)

Вот, лог сегодняшний (интервал 28 минут получается)
Nov 20 10:49:46>The firmware build date/time:20060522005529
Nov 20 10:49:46> DSL Carrier is down
Nov 20 10:50:16> DSL Carrier is up
Nov 20 10:50:18> PPPD Terminated Through Signal
Nov 20 10:50:18> Connection terminated.
Nov 20 10:50:19> pppd 2.4.3 started by root, uid 0
Nov 20 10:50:25> Connect: ppp0 {--} nas0
Nov 20 10:50:26> PPPoE Connect with IP Address 85.141.137.103
Nov 20 10:50:26> PPPoE Connection Successfully Established
Nov 20 10:50:26> PPPoE Connect with Gateway IP Address: 85.141.136.1
Nov 20 10:50:26> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 10:50:27> WAN IP address 85.141.137.103
Nov 20 10:50:27> WAN gateway 85.141.136.1
Nov 20 10:50:27> primary DNS address 212.188.4.10
Nov 20 10:50:27> secondary DNS address 195.34.32.116
Nov 20 11:17:27> DSL Carrier is down
Nov 20 11:18:07> DSL Carrier is up
Nov 20 11:18:10> PPPD Terminated Through Signal
Nov 20 11:18:10> Connection terminated.
Nov 20 11:18:11> pppd 2.4.3 started by root, uid 0
Nov 20 11:18:17> Connect: ppp0 {--} nas0
Nov 20 11:18:18> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 11:18:18> WAN IP address 85.141.136.110
Nov 20 11:18:18> PPPoE Connect with IP Address 85.141.136.110
Nov 20 11:18:19> PPPoE Connection Successfully Established
Nov 20 11:18:19> PPPoE Connect with Gateway IP Address: 85.141.136.1
Nov 20 11:18:19> WAN gateway 85.141.136.1
Nov 20 11:18:19> primary DNS address 212.188.4.10
Nov 20 11:18:19> secondary DNS address 195.34.32.116
Nov 20 11:45:17> DSL Carrier is down
Nov 20 11:45:47> DSL Carrier is up
Nov 20 11:45:49> PPPD Terminated Through Signal
Nov 20 11:45:49> Connection terminated.
Nov 20 11:45:50> pppd 2.4.3 started by root, uid 0
Nov 20 11:45:57> PPPoE Connect with IP Address 85.141.136.110
Nov 20 11:45:58> PPPoE Connection Successfully Established
Nov 20 11:45:58> PPPoE Connect with Gateway IP Address: 85.141.136.1
Nov 20 11:45:58> Connect: ppp0 {--} nas0
Nov 20 11:45:58> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 11:45:58> WAN IP address 85.141.136.110
Nov 20 11:45:58> WAN gateway 85.141.136.1
Nov 20 11:45:58> primary DNS address 212.188.4.10
Nov 20 11:45:58> secondary DNS address 195.34.32.116
Nov 20 12:13:08> DSL Carrier is down
Nov 20 12:13:38> DSL Carrier is up
Nov 20 12:13:41> PPPD Terminated Through Signal
Nov 20 12:13:41> Connection terminated.
Nov 20 12:13:42> pppd 2.4.3 started by root, uid 0
Nov 20 12:13:47> Connect: ppp0 {--} nas0
Nov 20 12:13:48> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 12:13:48> WAN IP address 85.141.136.110
Nov 20 12:13:48> PPPoE Connect with IP Address 85.141.136.110
Nov 20 12:13:49> PPPoE Connection Successfully Established
Nov 20 12:13:49> PPPoE Connect with Gateway IP Address: 85.141.136.1
Nov 20 12:13:49> WAN gateway 85.141.136.1
Nov 20 12:13:49> primary DNS address 212.188.4.10
Nov 20 12:13:49> secondary DNS address 195.34.32.116
Nov 20 12:40:48> DSL Carrier is down
Nov 20 12:41:28> DSL Carrier is up
Nov 20 12:41:30> PPPD Terminated Through Signal
Nov 20 12:41:31> Connection terminated.
Nov 20 12:41:32> pppd 2.4.3 started by root, uid 0
Nov 20 12:41:34> PPPoE Connect with IP Address 85.141.136.110
Nov 20 12:41:35> PPPoE Connection Successfully Established
Nov 20 12:41:35> PPPoE Connect with Gateway IP Address: 85.141.136.1
Nov 20 12:41:35> Connect: ppp0 {--} nas0
Nov 20 12:41:36> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 12:41:36> WAN IP address 85.141.136.110
Nov 20 12:41:36> WAN gateway 85.141.136.1
Nov 20 12:41:36> primary DNS address 212.188.4.10
Nov 20 12:41:36> secondary DNS address 195.34.32.116
Nov 20 13:08:38> DSL Carrier is down
Nov 20 13:09:08> DSL Carrier is up
Nov 20 13:09:11> PPPD Terminated Through Signal
Nov 20 13:09:11> Connection terminated.
Nov 20 13:09:12> pppd 2.4.3 started by root, uid 0
Nov 20 13:09:17> Connect: ppp0 {--} nas0
Nov 20 13:09:18> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 13:09:18> WAN IP address 91.76.63.55
Nov 20 13:09:18> PPPoE Connect with IP Address 91.76.63.55
Nov 20 13:09:19> PPPoE Connection Successfully Established
Nov 20 13:09:19> PPPoE Connect with Gateway IP Address: 91.76.60.1
Nov 20 13:09:19> WAN gateway 91.76.60.1
Nov 20 13:09:20> primary DNS address 212.188.4.10
Nov 20 13:09:20> secondary DNS address 195.34.32.116
Nov 20 13:36:28> DSL Carrier is down
Nov 20 13:36:58> DSL Carrier is up
Nov 20 13:37:00> PPPD Terminated Through Signal
Nov 20 13:37:00> Connection terminated.
Nov 20 13:37:01> pppd 2.4.3 started by root, uid 0
Nov 20 13:37:07> Connect: ppp0 {--} nas0
Nov 20 13:37:07> peer from calling number 00:30:88:00:3D:3F authorized
Nov 20 13:37:07> WAN IP address 85.141.136.163
Nov 20 13:37:07> PPPoE Connect with IP Address 85.141.136.163
Nov 20 13:37:08> PPPoE Connection Successfully Established
Nov 20 13:37:08> PPPoE Connect with Gateway IP Address: 85.141.136.1
...

я так понимаю, вот в этом месте:
DSL Carrier is down
DSL Carrier is up
что-то ломается. Что это такое?

PS:
пошевелил немного контакты, и стало
SNR Margin: 15 12 dB (Downstream, Upstream)

PS2:
Контакты поправил, но это
DSL Carrier is down
DSL Carrier is up
осталось.

Кстати, подключил я ZTE 831A II, он работает стабильно, и SNR Margin показывает за 20.

PS3:
Modulation T1.413 и G.dmt
SNR Margin: 9 18 dB (Downstream, Upstream)
Line Attenuation: 20 10 dB (Downstream, Upstream)
Data Rate: 6144 768 kbps (Downstream, Upstream)
в режиме G.dmt, вроде, работает стабильно, так что, вопрос, наверное, решён.