I've been having painfully slow downloads on my Cable TV boxes for the last couple of months and I've been trying to solve the problem. using port mirroring, I've managed to create a wireshark port capture of what is happening when I run a speed test on the cable tv box. The cable box IP is 192.168.55.253 in this case. http://www.megafileupload.com/97uX/portcapturefoxtelfailing.pcapng There seems to be a whole heap of TCP DUP ACK going on, would that have something to do with it? asked 08 Aug '15, 23:51  toddfraser88 |
2 Answers:
Let me rephrase the question: why does the speed test fail when connecting via a MikroTik router? The 'speed-test' consists of an HTTP GET request of a large (10576244) file. The succeeding speedtests via the netgear router do not show any packet loss. So unless you can convince the TV box to wait longer for a successful retransmission,to fix this problem you need to avoid the packet loss. As per http://wiki.mikrotik.com/wiki/Manual:Queue_Size - Default-small queue type "By default most of the queues in RouterOS have queue size of 10. " This is probably not enough to get a seamless packet-flow going . Maybe this problem is better addressed to the http://forum.mikrotik.com/ Regards Matthias answered 15 Aug '15, 09:00  mrEEde |
"There seems to be a whole heap of TCP DUP ACK going on, would that have something to do with it?" If you refer to 'it' as the slow downloads the answer is no. Regards Matthias answered 12 Aug '15, 00:22 mrEEde showing 5 of 8 show 3 more comments |
I've grabbed a port capture of when it's working.
it seems window size is identical when it's working properly.
http://www.megafileupload.com/97vX/portcapturefoxtelworking.pcapng
this is using an old netgear WNDR3700
the router i've replaced it with is a mikrotik RB951G-2HnD
Can you see anything in these capture results that might explain why it fails vs when its working?
I still need help with this.
So it seems that in the failling case the server stops sending 6 seconds before the FIN from the client comes. But the reason could not be seen...
do you think a port capture from the WAN port would help?
No, not really.
@toddfraser88
Your "answers" have been converted to comments as that's how this site works. Please read the FAQ for more information.
So the question you need an answer is: Why does the speed test fail to 192.168.55.253 when it succeeds to 192.168.1.145 ? Those are different TV boxes in different networks?
same modem, same tv box, same Ethernet cable, except in the working i put the mikrotik in switch mode and put the WNDR3700 in between it and the modem.
so the WNDR3700 does something differently that makes it work properly, I've no idea what though.
I've even tried reseting the mikrotik with no default configuration and setting it up entirely from scratch, even with the most basic config in place, the problem persists.