Looking at the modem lights, I can see regular long pauses
between packet sends.
I also recorded a bit of an ftp session with tcpdump:
11:18:45.433760 ppp14-11.rns.1073 > atheist.ftp-data: . 2048:3072(1024) ack 1 win 31744
11:18:45.433760 ppp14-11.rns.1073 > atheist.ftp-data: . 3072:4096(1024) ack 1 win 31744
11:18:46.439040 atheist.ftp-data > ppp14-11.rns.1073: . ack 3072 win 4096
11:18:46.439040 ppp14-11.rns.1073 > atheist.ftp-data: P 4096:5120(1024) ack 1 win 31744
11:18:48.010400 ppp14-11.rns.1073 > atheist.ftp-data: . 3072:4096(1024) ack 1 win 31744
11:18:48.635040 atheist.ftp-data > ppp14-11.rns.1073: . ack 4096 win 4096
11:18:48.635040 ppp14-11.rns.1073 > atheist.ftp-data: P 4096:5120(1024) ack 1 win 31744
11:18:49.240160 atheist.ftp-data > ppp14-11.rns.1073: . ack 5120 win 4096
11:18:49.240160 ppp14-11.rns.1073 > atheist.ftp-data: . 5120:6144(1024) ack 1 win 31744
11:18:49.240160 ppp14-11.rns.1073 > atheist.ftp-data: . 6144:7168(1024) ack 1 win 31744
11:18:50.235680 atheist.ftp-data > ppp14-11.rns.1073: . ack 6144 win 4096
11:18:50.235680 ppp14-11.rns.1073 > atheist.ftp-data: . 7168:8192(1024) ack 1 win 31744
11:18:51.836320 ppp14-11.rns.1073 > atheist.ftp-data: . 6144:7168(1024) ack 1 win 31744
11:18:52.646400 atheist.ftp-data > ppp14-11.rns.1073: . ack 7168 win 4096
11:18:52.646400 ppp14-11.rns.1073 > atheist.ftp-data: . 7168:8192(1024) ack 1 win 31744
11:18:53.232000 atheist.ftp-data > ppp14-11.rns.1073: . ack 8192 win 4096
11:18:53.232000 ppp14-11.rns.1073 > atheist.ftp-data: . 8192:9216(1024) ack 1 win 31744
Something interesting to note is that it is retransmitting
every second or third packet, even though an ack was received.
If I can provide any other information that might help solve
this problem, please ask -- this is very frustrating.
r~