Re: [Bloat] [e2e] bufferbloat paper

[Michael Richardson <mcr@sandelman.ca>]

Thanks for the reply, comments below.

>>>>> "Keith" == Keith Winstein <keithw@mit.edu> writes:
    >> Have you considered repeating your test with two phones?

    Keith> Yes, we have tried up to four phones at the same time.

    >> Can the download on phone1 affect the latency seen by a second phone?

    Keith> In our experience, a download on phone1 will not affect the unloaded
    Keith> latency seen by phone2. The cell towers appear to use a per-UE
    Keith> (per-phone) queue on uplink and downlink. (This is similar to what a
    Keith> commodity cable modem user sees -- I don't get long delays just
    Keith> because my neighbor is saturating his uplink or downlink and
    Keith> causing a 
    Keith> standing queue for himself.)

This is good news of a sort.
It means that there is no shared xmit queue on the tower, and that the
4G/LTE/whatever-they-call-it-today business of moving voice to VoIP is
going to do okay.   
The question then becomes: how to get all of one's low-latency traffic
onto that second channel!

-- 
]               Never tell me the odds!                 | ipv6 mesh networks [ 
]   Michael Richardson, Sandelman Software Works        | network architect  [ 
]     mcr@sandelman.ca  http://www.sandelman.ca/        |   ruby on rails    [