network performance 6.1 stable vs 4.9

[Michael Proto]

Stephen Clark wrote:
> Dominic Marks wrote:
> 
>> Stephen Clark wrote:
>>  
>>
>>> Hello List,
>>>
>>> We have a network appliance that is currently based on 4.9. We are in
>>> the process of releasing
>>> a new version based on 6.1 stable.
>>>   
>>
>> You are going to get asked this, so I'll ask first.
>>
>> Whats the reason behind not running a more recent STABLE? I understand
>> developing a product on a moving platform is not ideal, but its going to
>> be mentioned!
>>
>>  
>>
>>> In our testing using nttcp thru the appliance we see insignifant
>>> difference in thruput between the 2
>>> versions in a controlled environment - aproximately 94mbs on a 100mb
>>> lan.
>>>
>>> We have a person that is testing the both system inhouse surfing out
>>> over the internet on our T1
>>> link and he complains that he is consistently seeing the 6.1 version
>>> being much slower than the
>>> 4.9 version (on the same hardware).
>>> He has been comparing the 6.1 system to 4.9 system for a couple of weeks
>>> and continues to insist the 6.1 version is much slower.
>>>   
>>
>> You don't mention what the appliance actually does beyond just moving
>> packets about? Surfing implies some sort of proxy or gateway device?
>>
>>  
>>
>>> Are there any sysctl tunables that may affect performance going over the
>>> internet
>>> with a slower link, dropped packets, etc that could cause this?
>>>
>>> Any ideas would be appreciated.
>>>
>>>   
>>
>> Dominic
>>
>>  
>>
> Hi Dominic,
> 
> The appliance is basically a firewall/nat/vpn device. We started on 6.1
> last year and it has
> taken us a while to get things tested, plus I don't like to use a brand
> new release. If we go to
> a later release it means we have to do complete regression testing, etc.
> 
> We are basically using a GENERIC config for our kernel. We, meaning the
> R&D team don't see any
> performance issues in a controlled environment - 6.1 performs just as
> well as 4.9.
> 
> In subjective tests R&D has done using the following setup we see "no"
> problem:
> 
> freebsd+firefox <--100mbs lan---> 6.1 network appliance <----T1
> link----> internet
> freebsd+firefox <--100mbs lan---> 4.9 network appliance <----T1
> link----> internet
> 
> One of our testers has the same setup but is using winblows/ie in place of
> freebsd+firefox and subjectively says the 6.1 system is slower than the
> 4.9 system.
> 
> I was just wandering if there were any tunables that might cause this.
> 
> Thanks,
> Steve
> 

http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/configtuning-kernel-limits.html

The section on TCP Bandwidth Delay Product might be of a little assistance.


-Proto