[SR-Users] TCP read/write buffer size on per connection or per module basis

[Daniel-Constantin Mierla]

Hello,


On 02.05.17 13:02, M S wrote:
> Hi,
>
> I have a kamailio v4.4.5 deployment that serves TCP clients for SIP
> and XCAP requests (without SIP presence). The kamailio's core TCP
> parameters allow us to set TCP read and write buffer sizes which are
> set globally for all TCP connections.
>
> However, i noticed that in general SIP over TCP request is much
> smaller (<8KB for audio + video SIP INVITE request) then XCAP requests
> (say to support up to 500 contacts we need TCP buffers =~ 64KB). 
>
> So, if I set global TCP buffer size according to XCAP service needs
> (e.g. 64KB), they waste too much RAM for SIP connections (assuming max
> SIP packet is  8KB, there is 56KB buffer space wasted per connection).
>
> On the other hand, if i set global TCP buffer sizes to SIP service
> needs (e.g. 8KB) then it is insufficient for XCAP (only 70-80 contacts
> would fix in XCAP list).
>
> Therefore, i am looking for a way to allow TCP buffer size settings
> per connection OR per module basis. Is it possible? If so then how?
at this moment is not possible to set the buffer size per connection.
The connection structure is created before knowing what is going to be
received on it.

Also, not per module, because the module is agnostic of the transport layer.

An enhancement might be to specify it per socket, so when listening on
port 5060, then use a specific buffer size and when listening on another
port like 8060, use a different buffer size. But this requires C coding.

On the other hand, the latest kernels use the physical memory only when
writing. So if one allocates 2GB and uses only 10MB, only 10MB are used
from the physical memory, the rest is just virtual memory.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla
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