[tor-bugs] #1298 [Tor Client]: Tor does not treat multiple streams fairly

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#1298: Tor does not treat multiple streams fairly
-------------------------+--------------------------------------------------
  Reporter:  mikeperry   |       Owner:  nickm             
      Type:  defect      |      Status:  assigned          
  Priority:  major       |   Milestone:  Tor: 0.2.2.x-final
 Component:  Tor Client  |     Version:  0.2.1.24          
Resolution:  None        |    Keywords:                    
    Parent:              |  
-------------------------+--------------------------------------------------
Description changed by nickm:

Old description:

> Camilo Viecco noticed that Tor seems to have problems multiplexing
> streams onto the same circuit, and I have been
> able to reproduce this. In a simple test setup, I had 6 streams running
> on the same fast 2 hop circuit, and one stream
> would get 100-200K/s and the rest would only get 1K/s. He also ran the
> following experiments:
>
> "The tests that I made seem to show that the problem was on multiplexing
> multiple streams on the same circuit. I ran tests on a private Tor
> network and the problem seem to be limited to a per circuit limit .  (I
> tried multiple clients on the same host, using the same circuit path,
> and the problem seems to be related to the a circuit case, that is the
> 4th stream on each circuit ). The private network was using  a high
> speed low latency network (at most one router between hosts, with at
> least 1GBs paths between nodes, switches and routers).
>
> Therefore my guess is that the problem lies on the client or exit node
> socks code."
>
> Neither of us have yet tested the same client with different circuits, as
> this is difficult
> to pin down due to circuit performance variance.
>

> [Automatically added by flyspray2trac: Operating System: All]

New description:

 Camilo Viecco noticed that Tor seems to have problems multiplexing streams
 onto the same circuit, and I have been able to reproduce this. In a simple
 test setup, I had 6 streams running on the same fast 2 hop circuit, and
 one stream would get 100-200K/s and the rest would only get 1K/s. He also
 ran the following experiments:

 "The tests that I made seem to show that the problem was on multiplexing
 multiple streams on the same circuit. I ran tests on a private Tor network
 and the problem seem to be limited to a per circuit limit .  (I tried
 multiple clients on the same host, using the same circuit path, and the
 problem seems to be related to the a circuit case, that is the 4th stream
 on each circuit ). The private network was using  a high speed low latency
 network (at most one router between hosts, with at least 1GBs paths
 between nodes, switches and routers).

 Therefore my guess is that the problem lies on the client or exit node
 socks code."

 Neither of us have yet tested the same client with different circuits, as
 this is difficult to pin down due to circuit performance variance.

 Child Tickets:
 [[TicketQuery(parent=#1298)]]

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/1298#comment:21>
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