I am posting an old question again that hasn't been solved, forgive me, please.
I have an ADSL connection from BSNL (India) called Data One. I have installed Ubuntu 6.06 (Dapper). I have also configured pppoeconf and connect to the ISP using 'pon dsl-provider'. But after few minutes data transfer is stopped. Following an earlier suggestion, I changed the MTU and MRU values to 1492 in the /etc/ppp/options file, but that didn't solve the problem. It works perfectly in Fedora 5. How can I stay connected permanently to the internet in Ubuntu?

I think that we will need more information to help you troubleshoot that problem. Why don't you check the logs from ppoe and then write back if you find a pattern for the disconnection?

Dear avatarfx
I think, you mean ppp.log file. By default I don't get any ppp log file in Dapper. I included "local2.* -/var/log/ppp.log" entry in /etc/syslog.conf file, according to man page of plog and I now get the ppp.log in /var/log.
However, following is the entry of the said log file after connecting and disconnecting twice from the ADSL.

/var/log/ppp.log
Jul 25 17:30:40 darwin pppd[5379]: Plugin rp-pppoe.so loaded.
Jul 25 17:30:40 darwin pppd[5387]: pppd 2.4.4b1 started by biswanath, uid 1000
Jul 25 17:30:40 darwin pppd[5387]: PPP session is 1376
Jul 25 17:30:40 darwin pppd[5387]: Using interface ppp0
Jul 25 17:30:40 darwin pppd[5387]: Connect: ppp0 <--> eth0
Jul 25 17:30:43 darwin pppd[5387]: CHAP authentication succeeded: Authentication success,Welcome!
Jul 25 17:30:43 darwin pppd[5387]: CHAP authentication succeeded
Jul 25 17:30:43 darwin pppd[5387]: peer from calling number 00:E0:FC:4D:2E:BF authorized
Jul 25 17:30:43 darwin pppd[5387]: replacing old default route to eth0 [192.168.1.1]
Jul 25 17:30:43 darwin pppd[5387]: Cannot determine ethernet address for proxy ARP
Jul 25 17:30:43 darwin pppd[5387]: local IP address 59.93.200.91
Jul 25 17:30:43 darwin pppd[5387]: remote IP address 59.93.192.1
Jul 25 17:30:43 darwin pppd[5387]: primary DNS address 218.248.255.145
Jul 25 17:30:43 darwin pppd[5387]: secondary DNS address 61.1.96.71
Jul 25 18:08:43 darwin pppd[5387]: Terminating on signal 15
Jul 25 18:08:43 darwin pppd[5387]: Connect time 38.0 minutes.
Jul 25 18:08:43 darwin pppd[5387]: Sent 316408 bytes, received 1917801 bytes.
Jul 25 18:08:43 darwin pppd[5387]: restoring old default route to eth0 [192.168.1.1]
Jul 25 18:08:43 darwin pppd[5387]: Connection terminated.
Jul 25 18:08:43 darwin pppd[5387]: Exit.
Jul 25 18:09:40 darwin pppd[6470]: Plugin rp-pppoe.so loaded.
Jul 25 18:09:40 darwin pppd[6472]: pppd 2.4.4b1 started by biswanath, uid 1000
Jul 25 18:09:40 darwin pppd[6472]: PPP session is 5755
Jul 25 18:09:40 darwin pppd[6472]: Using interface ppp0
Jul 25 18:09:40 darwin pppd[6472]: Connect: ppp0 <--> eth0
Jul 25 18:09:40 darwin pppd[6472]: CHAP authentication succeeded: Authentication success,Welcome!
Jul 25 18:09:40 darwin pppd[6472]: CHAP authentication succeeded
Jul 25 18:09:40 darwin pppd[6472]: peer from calling number 00:E0:FC:4D:2E:BF authorized
Jul 25 18:09:41 darwin pppd[6472]: replacing old default route to eth0 [192.168.1.1]
Jul 25 18:09:41 darwin pppd[6472]: Cannot determine ethernet address for proxy ARP
Jul 25 18:09:41 darwin pppd[6472]: local IP address 59.93.198.108
Jul 25 18:09:41 darwin pppd[6472]: remote IP address 59.93.192.1
Jul 25 18:09:41 darwin pppd[6472]: primary DNS address 218.248.255.145
Jul 25 18:09:41 darwin pppd[6472]: secondary DNS address 61.1.96.71
Jul 25 18:25:50 darwin pppd[6472]: Terminating on signal 15
Jul 25 18:25:50 darwin pppd[6472]: Connect time 16.2 minutes.
Jul 25 18:25:50 darwin pppd[6472]: Sent 488803 bytes, received 23666663 bytes.
Jul 25 18:25:50 darwin pppd[6472]: restoring old default route to eth0 [192.168.1.1]
Jul 25 18:25:50 darwin pppd[6472]: Connection terminated.
Jul 25 18:25:50 darwin pppd[6472]: Exit.