Efficiency of long-RTT forward

Nikos Mavrogiannopoulos n.mavrogiannopoulos at gmail.com
Mon Apr 18 06:09:25 PDT 2016

On Mon, Apr 18, 2016 at 1:27 PM, Yick Xie <yick.xie at gmail.com> wrote:
> Hi,
> Recently I found that sometimes ocserv experienced a bandwidth loss
> when fetching files from remote (long-RTT) servers, compared with
> local(short-RTT) servers.
> e.g.
> Client- > VPN, a same file on server A(<10ms) and B(100ms). The gap of
> throughput can reach up to 5 times(even more) in fetching this file
> from A than B. When we download it from A, the bandwidth(between
> clients and VPN) could almost be fully utilized, while as I said the
> situation become worse when it comes to B. One sure thing is no
> bottleneck of bandwidth between VPN and server B using wget/curl.
> Hence I just suspect the issue might fall on the forward buffer. Any
> optimization shall be taken into consideration?

Hi Yick,
 Have you tried playing with output-buffer? The defaults are optimized
mainly for voip usage, so if you require high bandwidth you should
probably increase the default value (10), to 100 or even 1000. Could
you please report back any findings from this change, so I can
document it if it is successful?


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