[Bloat] T-Mobile LTE buffer bloat

[Dirk Kutscher]

Also, it would be important to understand what radio access technology the LTE-WiFi-GW was really using at the time of the measurement. In hybrid GSM/UMTS/LTE networks (like T-Mobile's), mobile phones frequently fall back to GSM (GPRS), so you cannot blame LTE in this case.

There are many myths around bufferbloat in mobile networks. You really need to understand the specifics of the network, its utilization at a given time -- and the deficiencies of the gear you are using.

Having said that, in LTE there are apparently significant differences in latency (variation) depending on the operator and equipment vendor. For example, I have seen LTE measurements from hotspot areas in Tokyo that still looked much better (max 60 ms uplink delay) than what I hear sometimes from friends in the US.

It's about time for structured measurement campaign that helps us to analyze this better.

Best regards,
Dirk



> -----Original Message-----
> From: bloat-bounces at lists.bufferbloat.net [mailto:bloat-
> bounces at lists.bufferbloat.net] On Behalf Of Mikael Abrahamsson
> Sent: Donnerstag, 31. Oktober 2013 01:02
> To: Stephen Hemminger
> Cc: bloat at lists.bufferbloat.net
> Subject: Re: [Bloat] T-Mobile LTE buffer bloat
> 
> On Wed, 30 Oct 2013, Stephen Hemminger wrote:
> 
> > There is zero configuration of proxy, it is just a LTE <-> wifi hotspot.
> > I suspect some caching (or commercial interest) at their end.
> 
> I have no insight in how T-Moble does things, but I know that vendors pitch
> video/image compression stuff and you want to put it *before* it goes out
> the radio network (because that's the expensive resource), so that's why my
> guess it's doing the image-rewriting not in the end user box, but in a centrally
> placed device in their network.
> 
> --
> Mikael Abrahamsson    email: swmike at swm.pp.se
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