Strange TCP connection behavior 2.0 RC2 (+3)

Ryan Malayter malayter at
Wed Jun 29 12:59:49 UTC 2011

On Jun 28, 3:35 pm, Cameron Byrne < at> wrote:

> AFAIK, Verizon and all the other 4 largest mobile networks in the USA
> have transparent TCP proxies in place.

Do you have a reference for that information?  Neither AT&T nor Sprint
seem to have transparent *HTTP* proxies according to I would have thought that
would be the first and most important optimization a mobile carrier
could make. I used to see "mobile-optimized" images and HTTP
compression for sites that weren't using it at the origin on Verizon's
3G network a few years ago, so Verizon clearly had some form of HTTP
proxy in effect.

Aside from that, how would one check for a transparent *TCP* proxy? By
looking at IP or TCP option fingerprints at the receiver? Or comparing
TCP ACK RTT versus ICMP ping RTT?

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