Return-Path: Date: Thu, 14 Oct 2004 11:30:18 -0400 (EDT) From: "Jay W. Summet" To: Marcel Holtmann cc: bluez-users@lists.sourceforge.net Subject: Re: [Bluez-users] Socket CF adaptor, limited to 2-3KB/sec RFCOMM PPP connection? In-Reply-To: <1097752969.4640.40.camel@notepaq> Message-ID: References: <1097752969.4640.40.camel@notepaq> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII List-ID: >>New Information: In response to requests for hcidump -t log files and testing with a USB bluetooth adaptor and obex push.<< I have a Socket Compact Flash bluetooth adaptor, which uses the dtl1_cs kernel module. I have it configured, and everything works, but I am getting very slow GPRS speeds with my Sony Ericsson T610 telephone. I first noticed it with my GPRS data transfer when I only got 1.9 to 2.2 KB per second of throughput on downloads. When I use IrDA to connect to my phone instead of bluetooth, I get the expected 5.0 to 5.6 KB per second of throughput. I borrowed a friend's USB bluetooth adaptor (DBT-120 D-Link) and am able to get the 5.0 to 5.6 KB/sec GPRS transfer while the Socket Compact Flash (CF) adaptor got 2.0KB/sec. (Tested in the same location, with excellent cellular signal strength, at the same time of day.) I also tested both devices using the obextool to "push" an 84 KB jpeg image to my telephone. I believe that this transfer was speed limited by the phone's internal (flash?) memory, as with both the Socket CF and D-Link USB adaptor I got about the same speeds, in the 24-30 second range (best case, in a few cases I got much worth throughput). [That's about 3.4KB/Sec, slower than the GPRS throughput (below) I was getting with the USB adaptor or IrDA, even when I was using the USB adaptor for the obex push.] I've captured an "hcidump -t" log file of the two different GPRS phone connections. In both cases, I used the same software and scripts, initializing a PPP connection to the internet and using wget to download the first part of an AVI file for a minute until the transfer speed evened out. With the Socket CF card, I got around 2.0KB/sec, while with the USB Bluetooth adaptor I got around the expected GPRS max speed at 5.3KB/sec. files: Slow, Socket CF card: http://www.cc.gatech.edu/~summetj/drafts/socket_cf_gprs_2.0K.dump Fast enough D-Link USB dongle: http://www.cc.gatech.edu/~summetj/drafts/usb_gprs_5.3K.dump I paid extra for the CF form factor, as I have an internal CF slot, and don't want to have a usb dongle sticking out of my computer if I can at all avoid it, so I'm motivated to get this sucker working correctly. Radio strength isn't an issue, as the phone was about 2 feet from the laptop in both tests, and the CF card has worked at 2.0K (gprs) from at least 20 feet away. (and at 3.4KB/sec for OBEX push) I have compiled the 2.6.7 (kernel.org stock) kernel for my laptop, and am willing to apply patches and re-compile to test if somebody has an idea of something that may fix this... Thanks, Jay