Alekz:
Да. Я уже пробовал его перезагружать. Вот вывод консоли:

sip*CLI> module reload res_features
-- Reloading module 'res_features.so' (Call Features Resource)
== Parsing '/etc/asterisk/features.conf': Found
-- Added extension '700' priority 1 to parkedcalls

Подозрительно немногословный вывод ИМХО.

Еще один момент. Об этом, видимо, надо было сказать сразу:

Asterisk 1.4.17~dfsg-2ubuntu1 built by buildd @ vernadsky on a i686 running Linux on 2008-04-12 07:08:45 UTC

Установлен из репозитория Ubuntu 8.04.

Можно лог звонка (без sip debug) с неудачной попыткой перевода?

кто пытается перевести, звонящий или вызываемый?

пропишите

Dial(SIP/${EXTEN},120,tT)

-- Executing [326@office:1] Dial("SIP/289-b7c13348", "SIP/326|120|t") in new stack
-- Called 326
-- SIP/326-082cd490 is ringing
-- ast_get_srv: SRV lookup for '_sip._udp.sipnet.ru' mapped to host sipnet.ru, port 5060
-- SIP/326-082cd490 answered SIP/289-b7c13348
[Feb 12 14:45:26] DTMF[8107]: channel.c:2463 __ast_read: DTMF begin '#' received on SIP/326-082cd490
[Feb 12 14:45:26] DTMF[8107]: channel.c:2473 __ast_read: DTMF begin passthrough '#' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2400 __ast_read: DTMF end '#' received on SIP/326-082cd490, duration 100 ms
[Feb 12 14:45:27] DTMF[8107]: channel.c:2441 __ast_read: DTMF end accepted with begin '#' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2457 __ast_read: DTMF end passthrough '#' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2463 __ast_read: DTMF begin '1' received on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2473 __ast_read: DTMF begin passthrough '1' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[32479]: channel.c:2400 __ast_read: DTMF end '1' received on SIP/326-082cd490, duration 80 ms
[Feb 12 14:45:27] DTMF[32479]: channel.c:2441 __ast_read: DTMF end accepted with begin '1' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[32479]: channel.c:2457 __ast_read: DTMF end passthrough '1' on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2400 __ast_read: DTMF end '1' received on SIP/326-082cd490, duration 80 ms
[Feb 12 14:45:27] DTMF[8107]: channel.c:2417 __ast_read: DTMF end '1' put into dtmf queue on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2273 __ast_read: DTMF begin emulation of '1' with duration 100 queued on SIP/326-082cd490
[Feb 12 14:45:27] DTMF[8107]: channel.c:2520 __ast_read: DTMF end emulation of '1' queued on SIP/326-082cd490
[Feb 12 14:45:33] DTMF[8107]: channel.c:2463 __ast_read: DTMF begin '#' received on SIP/326-082cd490
[Feb 12 14:45:33] DTMF[8107]: channel.c:2473 __ast_read: DTMF begin passthrough '#' on SIP/326-082cd490
[Feb 12 14:45:33] DTMF[8107]: channel.c:2400 __ast_read: DTMF end '#' received on SIP/326-082cd490, duration 80 ms
[Feb 12 14:45:33] DTMF[8107]: channel.c:2441 __ast_read: DTMF end accepted with begin '#' on SIP/326-082cd490
[Feb 12 14:45:33] DTMF[8107]: channel.c:2457 __ast_read: DTMF end passthrough '#' on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[8107]: channel.c:2463 __ast_read: DTMF begin '1' received on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[8107]: channel.c:2473 __ast_read: DTMF begin passthrough '1' on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[32479]: channel.c:2400 __ast_read: DTMF end '1' received on SIP/326-082cd490, duration 100 ms
[Feb 12 14:45:34] DTMF[32479]: channel.c:2441 __ast_read: DTMF end accepted with begin '1' on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[32479]: channel.c:2457 __ast_read: DTMF end passthrough '1' on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[8107]: channel.c:2400 __ast_read: DTMF end '1' received on SIP/326-082cd490, duration 100 ms
[Feb 12 14:45:34] DTMF[8107]: channel.c:2436 __ast_read: DTMF begin emulation of '1' with duration 100 queued on SIP/326-082cd490
[Feb 12 14:45:34] DTMF[8107]: channel.c:2520 __ast_read: DTMF end emulation of '1' queued on SIP/326-082cd490
== Spawn extension (office, 326, 1) exited non-zero on 'SIP/289-b7c13348'

sip.conf

[326] ;xlite
type=friend
host=dynamic
username=326
secret=326
nat=no
canreinvite=no
allowtransfer=yes
cancallforward=yes
context=office
callerid="Alex K" <326>
disallow=all
allow=ulaw
allow=alaw
;dtmfmode=info

[289] ;Planet
type=friend
host=dynamic
username=289
secret=289
nat=no
allowtransfer=yes
cancallforward=yes
canreinvite=no
context=office
callerid="Igor" <289>
disallow=all
allow=ulaw
allow=alaw
;dtmfmode=info
----------------------------

Все время звонил с 289 на 326, с 326 - звонок никак не переводился.
Попробовал с 326 позвонить на 289 - звонок с 289 перевелся на ура.

Позвонил с третьего номера (конфиг идентичен 289) на 289 - не переводится.
Подчеркну, что переводить всегда пытался с ВЫЗЫВАЕМОГО номера.

Попробуйте увеличить значение

featuredigittimeout = 500 ; Max time (ms) between digits for feature activation

Alekz:
Увеличил до 1500 - Помогло. Большое спасибо! Тему можно считать закрытой!