I have a situation where I would like to introduce an artificial delay of
100 milliseconds to incoming UDP traffic to a particular client. Here is my
setup:
+-------+ +-----------+
| Linux | | |
''Internet''---eth1| NAT |eth0======|192.168.1.4|
| | | |
+-------+ +-----------+
Note I''m not looking to restrict the RATE or SPEED at all, just to add
a
DELAY, and only to incoming UDP packets coming in from the Internet destined
for 192.168.1.4. I have kernel 2.4.20 with all the latest and greatest tc,
htb patches, etc.
Can anyone help??
Thanks much,
+Ryan
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hi ryan, i had asked a similar question a while back, and stef recommended the following: http://snad.ncsl.nist.gov/itg/nistnet make sure to read the faq! cheers charles On Sun, 2003-06-08 at 01:19, Ryan Agler wrote:> I have a situation where I would like to introduce an artificial delay of > 100 milliseconds to incoming UDP traffic to a particular client. Here is my > setup: > > +-------+ +-----------+ > | Linux | | | > ''Internet''---eth1| NAT |eth0======|192.168.1.4| > | | | | > +-------+ +-----------+ > > Note I''m not looking to restrict the RATE or SPEED at all, just to add a > DELAY, and only to incoming UDP packets coming in from the Internet destined > for 192.168.1.4. I have kernel 2.4.20 with all the latest and greatest tc, > htb patches, etc. > > Can anyone help?? > > Thanks much, > +Ryan > > > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/_______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
Hi Charles, Thanks for your response! I followed your advice and installed the nistnet kernel module, and after a lot of wrestling it worked. Ill explain why I need a delay to incoming UDP traffic -- 192.168.1.4 is a Cisco ATA-186 Analog Telephone Adaptor, which lets me hook up a normal phone/fax machine and place calls over the Internet. It turns out that there is a slight asymmetric delay, i.e. the time between when I speak into the phone and its heard by the person I call is longer than the time between her speaking and me hearing it. This is fine for voice, but intolerable to my fax machine. So, I used the nistnet module to delay incoming UDP packets to 192.168.1.4 by 300 milliseconds, and got the ''symmetric'' delay I was seeking and faxes are working! I am wondering if anyone out there can think of another delaying solution using a qdisc?? I had many problems getting the nistnet module installed; it refused to coexist with an lt_serial module that allows my faxmodem to work, and causes sporadic fits with my kernel. Any advice is appreciated! Thanks, +Ryan -----Original Message----- From: Charles Shick [mailto:chuck.shick@manchotnetworks.net] Sent: Sunday, June 08, 2003 4:12 AM To: Ryan Agler Subject: Re: [LARTC] Artificial latency hi ryan, i had asked a similar question a while back, and stef recommended the following: http://snad.ncsl.nist.gov/itg/nistnet make sure to read the faq! cheers charles On Sun, 2003-06-08 at 01:19, Ryan Agler wrote:> I have a situation where I would like to introduce an artificial delay of > 100 milliseconds to incoming UDP traffic to a particular client. Here ismy> setup: > > +-------+ +-----------+ > | Linux | | | > ''Internet''---eth1| NAT |eth0======|192.168.1.4| > | | | | > +-------+ +-----------+ > > Note I''m not looking to restrict the RATE or SPEED at all, just to add a > DELAY, and only to incoming UDP packets coming in from the Internetdestined> for 192.168.1.4. I have kernel 2.4.20 with all the latest and greatesttc,> htb patches, etc. > > Can anyone help?? > > Thanks much, > +Ryan > > > _______________________________________________ > LARTC mailing list / LARTC@mailman.ds9a.nl > http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/_______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
hello ryan,> So, I used the nistnet module to delay incoming UDP packets > to 192.168.1.4 by 300 milliseconds, and got the ''symmetric'' delay I was > seeking and faxes are working!good news, alhtough I am curious how you are connected to the internet? also, did you check with cisco?> I am wondering if anyone out there can think of another delaying solution > using a qdisc??i am not aware but would also be interested -- please do post back should you find anything ...> I had many problems getting the nistnet module installed; > it refused to coexist with an lt_serial module that allows my faxmodem to > work, and causes sporadic fits with my kernel.yes, i experienced similar issues, but managed to get it stable for some very simple testing -- i need to do more. cheerio charles _______________________________________________ LARTC mailing list / LARTC@mailman.ds9a.nl http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/