Merlin U720 USB and Linux?

toutenhoofd · EVDO Fledgling Joined: 08 Sep 2005 Posts: 11

Any word on using the Merlin U720 USB Rev A modem with Linux? If it works I'd like to order one Smile

pcfreak · EVDO Newbie Joined: 10 Dec 2006 Posts: 4

I just got my U720, and haven't been able to get it working with Ubuntu 6.10. If anyone has the U720 working in Linux, please let me know.

futrader · EVDO Newbie Joined: 12 Dec 2006 Posts: 7

I don't own this, but I'm thinking about it. You might need to patch your kernel. See, for example: http://marc2.theaimsgroup.com/?l=linux-mm-commits&m=116577893917749&w=2

I gather this should allow the kernel to recognize the modem, and then you would just need the normal linux ppp scripts.

mccorkle · EVDO Newbie Joined: 15 Dec 2006 Posts: 3

I'm running (k)ubuntu 6.06LTS on a rack mounted box in a car, and I've got the Merlin U720 working like a champ. Its a little convoluted, but the end result is that I didn't have to patch/recompile my kernel, and the thing auto connects anytime the modem is plugged in with a 10 second delay if anything ever makes the signal drop. Details are below, and parts are credit to codef0x's post over at http://www.evdoforums.com/thread3308.html.

Please NOTE: You have to "register" the modem with your cell provider via any Microsoft Windows box first. I tried it from a vmware emulated windows XP pro box and failed, ymmv.

First, get the module to load on boot by editing /etc/modules:

pcfreak · EVDO Newbie Joined: 10 Dec 2006 Posts: 4

Thanks mccorkle! Your instructions worked like a charm. I now have my U720 running in Ubuntu.

meddle93 · EVDO Newbie Joined: 16 Dec 2006 Posts: 2

I am posting under knoppix 5.01 (dvd) using a novatel u720. I am assuming this is the same as the merlin u720 since the product and vendor id's are the same.

connecting on this system is very easy once you know what to do.

First, make sure that there is no other routing info. I had a wireless router connected for a lan and this was preventing the peerdns from working properly.

next activate usbserial using the same command as above

mccorkle · EVDO Newbie Joined: 15 Dec 2006 Posts: 3

Glab I could help. I'm still hacking on the "registration" part -- I'd really like to be able to get these things out of the box and have them work in linux direct without the registration in windows.

toutenhoofd · EVDO Fledgling Joined: 08 Sep 2005 Posts: 11

I'd love to have some of you who successfully have the U720 working with Linux report on your downstream and upstream performance. Anyone care to post some results? And it would be even better if you could compare the Linux speeds with the speeds you get from Windows.

Thanks.

mccorkle · EVDO Newbie Joined: 15 Dec 2006 Posts: 3

I'm driving about 400 miles this weekend (from Jacksonville, FL to Tallahassee, FL with lots of really out of the way stops between) and I'll be running mtr and hitting speakeasy's speadtest every time I stop the car... I'll upload the report when I get done.

I'll be using a U720 with Ubuntu 6.06LTS and the 2.6.15-27 kernel.

pcfreak · EVDO Newbie Joined: 10 Dec 2006 Posts: 4

Here are my results:

Linux
Download Speed: 477 kbps (59.6 KB/sec transfer rate)
Upload Speed: 130 kbps (16.3 KB/sec transfer rate)

Windows
Download Speed: 1517 kbps (189.6 KB/sec transfer rate)
Upload Speed: 114 kbps (14.3 KB/sec transfer rate)

I'm using the same laptop (Dell M1210) and I'm dual booting WinXP and Ubuntu 6.10. I ran the speakeasy speed test several times, and the results are pretty much the same each time. Anyone know why the download speeds vary so much between Windows and Linux?

adewolf · EVDO Newbie Joined: 29 Apr 2005 Posts: 4

Any ideas why Linux is almost 3 times slower??

teststrips · EVDO Newbie Joined: 27 Dec 2006 Posts: 7

packet size (MTU)? - just a theory. I used this at a friend's house to speed up his DSL. - http://www.debianhelp.co.uk/mtu.htm

edit, i see you are on ubunto... this might be better
http://www.debianadmin.com/change-mtu-maximum-transmission-unit-of-network-interface.html#more-119
or
http://ubuntuforums.org/archive/index.php/t-82093.html

pcfreak · EVDO Newbie Joined: 10 Dec 2006 Posts: 4

I tried adjusting MTU on the ppp0 interface while in Ubuntu. Speed test results were pretty much the same.

toutenhoofd · EVDO Fledgling Joined: 08 Sep 2005 Posts: 11

Help from Linux Masters!

I'm convinced that most everyone who uses EVDO on Linux, regardless of the carrier or the modem, has a slow connection. The one exception might be the Kyocera KR1, which runs Linux and I believe is pretty fast. I've tried several Linux distros, 2.4 and 2.6 kernels, and I've never gotten speeds equivalent to what I get on my Mac or WinXP. Anyone out there have speed comparisons between Linux and OS X or WinXP to show otherwise? I'd love to see them.

There must be a simple solution... Please help us you Linux Masters...

futrader · EVDO Newbie Joined: 12 Dec 2006 Posts: 7

Using a gentoo linux, if I use the 2.6.20-rc2-mm1 kernel sources (Andrew Morton's experimental sources) I get results like this:

But, using gentoo 2.6.19-r2 sources (no extra patches), I get results like this:

The results are repeatable. This is a kernel issue, and I think there are patches floating around that fix the problem.