Re: [Openvpn-users] Samba performance and ICMP

[Colin R. <co...@ca...>]

David Hough wrote:
> Leonardo Rodrigues Magalhães wrote:
>   
>>     from time to time we always have someone complaining about M$ File 
>> Sharing protocols performance, even with Microsoft or with 3rd party 
>> implementations (Samba). I've seen these complains on OpenVPN lists, on 
>> IPSec lists, on every kind of network-related lists when there's a low 
>> bandwidth/little higher latency connection involved. Not only VPN, but 
>> even with WAN links.
>>
>>     It seems to me that Microsoft file sharing protocols were simply not 
>> designed for those low bandwidth/little higher latency situations. It's 
>> interesting to compare these M$ file sharing protocols with other 
>> standards protocols, like HTTP/SMTP/FTP/whatever, which are purely TCP 
>> ones, and compare that they perform pretty nice on any kind of 
>> situation, being limited only by the bandwidth involved.
>>
>>     But M$ sharing protocols no ..... they work fine on LAN networks but 
>> when it comes to WAN/VPN, it simply sucks.
>>
>>     it can be some workarounds to make it a little worst, but it's clear 
>> to me that the protocol simply wasnt designed having these connections 
>> in mind. It seems clear to me that it was designed to run LAN only.
>>
>>
>>     
> SMB is very poor when used over a link with a high latency, regardless 
> of whether it's OpenVPN or something else. Unfortunately you're stuck 
> with it as soon as you leave your LAN behind. There are caching 
> solutions available that can reduce the effects, but they are more use 
> for inter-office VPN solutions where your local office can cache stuff 
> from the remote end and give a better response time to local queries.
>
> Dave
>
>   

Dave et. al. speak the truth don't waste your time trying to fix the 
un-fixable. SMB is crap pure and simple. As I recall the biggest issue 
is that there is a little bit of "hi I need some more data, ok here's 
some more data" client->server chatter every 64k of data, that's right 
64k. This is horribly exaggerated on relatively "slow" high-latency 
links that even a decent Internet connection represents. Even take a 
moment to compare SMB transfer times over the LAN versus FTP or even 
HTTP and you'll see exactly how ugly this protocol is.

Too much detail on SMB can be found here: 

http://www.phrack.org/issues.html?issue=60&id=11#article

I with the truth were otherwise.

C