Hi everyone, I was wondering if anyone could clear up some confusion I have regarding UDP packet loss.
Scenario: I rent a VPS from OVH and run a VOIP server on it. Recently there's been a fairly high (10%) rate of packet loss for all users so I came to the conclusion that it was server side.
After contacting OVH with iperfs as proof, they sent the following message:
Hi
Thank you for providing me with the information, however your test is based on the UDP protocol.
UDP uses a simple connectionless transmission model with a minimum of protocol mechanism. It has no handshaking dialogues, and thus exposes any unreliability of the underlying network protocol to the user's program. There is no guarantee of delivery, ordering, or duplicate protection.
Under UDP there can be packet loss, this is why TCP is used.
My MTR doesn't indicate any packet loss over 20 packets:
Start: Fri Jul 17 15:32:50 2015
HOST: Loss% Snt Last Avg Best Wrst StDev
1.|-- balance-5418 0.0% 20 0.3 0.3 0.2 0.4 0.0
2.|-- host81-148-128-1.in-addr. 0.0% 20 10.3 25.1 9.5 144.8 35.3
3.|-- 213.120.182.141 0.0% 20 9.7 26.4 9.5 161.3 40.6
4.|-- 213.120.161.82 0.0% 20 10.9 22.4 10.1 148.1 33.7
5.|-- 31.55.164.55 0.0% 20 10.4 23.5 9.9 111.3 30.7
6.|-- 31.55.164.107 0.0% 20 10.8 17.2 10.2 63.8 16.7
7.|-- acc1-10GigE-0-2-0-13.bm.2 0.0% 20 16.1 17.7 16.1 33.6 4.0
8.|-- core1-te0-15-0-17.ilford. 0.0% 20 19.5 20.7 16.5 53.3 8.0
9.|-- peer6-te0-10-0-14.telehou 0.0% 20 18.0 20.8 17.4 75.9 13.0
10.|-- 
100.0 20 0.0 0.0 0.0 0.0 0.0
11.|-- gra-g1-a9.fr.eu 0.0% 20 21.1 27.8 20.4 88.5 17.7
12.|-- rbx-s9-a9.fr.eu 0.0% 20 20.6 29.4 20.3 111.5 25.7
13.|-- 136.ip-5-196-17.eu 0.0% 20 22.0 31.9 21.4 115.3 24.3
14.|-- [my domain] 0.0% 20 25.2 36.6 20.8 158.8 37.7
The iperf which you have sent shows the bandwidth at 100 Mbits/sec. For me there isn't any issues regarding bandwidth nore packet loss on the server.
Surely if there's UDP packet loss then that's an issue and should be sorted out rather than basically saying "use TCP"?
