[e2e] Packet reordering in Internet

[Per Hurtig (work)]

Is reordering a problem for datacenters?

Thanks, Per Hurtig

On Thu, Aug 13, 2009 at 03:06, rick jones<perfgeek at mac.com> wrote:
>
> On Aug 12, 2009, at 8:32 AM, Manish Jain wrote:
>
>> Thanks everyone for the useful pointers.
>>
>> Based on the some pointers and past discussions, I understand that
>> routers in the current Internet have load-balancing implemented in a
>> way to preserve packet order within a TCP flow. Is that a safe
>> assumption? Are there any other mechanisms in the routers/switches
>> that could lead to packet reordering?
>
> Define "safe." Correct more than 1/2 the time?  More than 3/4? 7/8? 99 times
> out of 10?-)
>
> If the "router" is made from "Linux" the Linux bonding (aka load balancing,
> aggregation, teaming, trunking, call-it-what-you-will) software does offer a
> "round-robin" option that will spread packets of the same flow across
> multiple links and will indeed lead to reordering.
>
> rick jones
>
>>
>> --
>> Manish
>>
>> On Wed, Aug 12, 2009 at 9:50 AM, Bartek Belter<bart at man.poznan.pl> wrote:
>>>
>>> Hi Manish,
>>>
>>> Some time ago we did some experiments in the pan-European education
>>> network. The results of experiments were summarized in a paper.
>>> It is available here:
>>> http://tnc2005.terena.org/core/getfile.php?file_id=626 (Shall we worry about
>>> Packet Reordering?).
>>>
>>> Hope it helps.
>>>
>>> Best regards,
>>> Bartek
>>>
>>> -----Original Message-----
>>> From: end2end-interest-bounces at postel.org
>>> [mailto:end2end-interest-bounces at postel.org] On Behalf Of Manish Jain
>>> Sent: Tuesday, August 11, 2009 11:57 PM
>>> To: end2end-interest at postel.org
>>> Subject: [e2e] Packet reordering in Internet
>>>
>>> Hello,
>>>
>>> I was wondering if there are measurement studies of Internet traffic
>>> quantifying the magnitude of packet reordering within a TCP flow. Is
>>> reordering a common problem for TCP in the current Internet? How about the
>>> load balancing features in the routers from major vendors : is it per flow
>>> basis or per packet basis, and if flow based load balancing is done, then
>>> how is the flow classification is done these routers?
>>> What could be/are other sources of reordering withing a TCP flow?
>>>
>>> Thanks,
>>> Manish
>>>
>>>
>>>
>>
>
> there is no rest for the wicked, yet the virtuous have no pillows
>
>
>