Re: [Discuss-gnuradio] Calculating the delay of TCP link.
Its not quite that simple and the other factors are not negligible by any means. The recommended approach would be to download Wireshark, capture the traffic and analyse it in the Throughput Graph. You can adapt the Wireshark setup from this: http://www.dslreports.com/faq/15888 Regards, Mark McCarron Date: Thu, 2 May 2013 11:17:45 -0700 From: engrsajjadsaf...@yahoo.com Subject: Re: [Discuss-gnuradio] Calculating the delay of TCP link. To: mark.mccar...@live.co.uk Actually i want to calculate the delay using the formula like Assuming all other factors as negligible.Here we have 1500 byte tcp header, which in bits is 1500*8/50KHz. Here the R is in kHz but to use this formula we have to have R in Bits per second. Is my way of calculating is right from this approach or not? Best Regards,SAJJAD SAFDAR From: Mark McCarron mark.mccar...@live.co.uk To: Sajjad Safdar engrsajjadsaf...@yahoo.com Sent: Wednesday, May 1, 2013 12:51 AM Subject: RE: [Discuss-gnuradio] Calculating the delay of TCP link. The MTU will only tell you if there is fragmentation. In packet switched networks, there can be delays for any number of reasons that are not entirely predictable. For example, assume someone is watching a video, using VOIP, downloading, etc. These can place heavy load on a switch, router or hub and saturate buffers delaying your packets and reducing throughput. Other factors such as QoS or traffic shaping can alter things. Then you have cosmic rays, bad wires, failing circuitry, etc. Then on a PC the network stack itself can be a source of delays as this is implemented in software a dependent on the scheduler and what else is happening in the machine. Trying to monitor all this, only places additional load on these systems a skews your results. The best you can do is attempt to define an average and identify the worst case scenario. Aiming between these two figures will normally provide you with a robust service that exceeds expectation. Regards, Mark McCarron Date: Tue, 30 Apr 2013 12:40:07 -0700 From: engrsajjadsaf...@yahoo.com Subject: Re: [Discuss-gnuradio] Calculating the delay of TCP link. To: mark.mccar...@live.co.uk Hi,Is it any way to calculate using the MTU size of TCP packet and the sampling rate, like a mathematical approach using formulas. Best Regards,SAJJAD SAFDAR From: Mark McCarron mark.mccar...@live.co.uk To: Sajjad Safdar engrsajjadsaf...@yahoo.com Sent: Tuesday, April 30, 2013 12:33 AM Subject: RE: [Discuss-gnuradio] Calculating the delay of TCP link. Calculating delay is complex. If you just want to know the average time between hosts on an IP network, then use the Ping command. It has a RTT value in ms. Just remember that on a packet switched network, this can vary but is typically under 1ms in a local environment. Similar delays exist throughout the receive chain and processor, which are virtually impossible to measure accurately. Accurate measurements like for radar, or bearings are impossible without some form of time-stamp at the receiver and that would require an atomic clock chip. Regards, Mark McCarron Date: Mon, 29 Apr 2013 12:01:57 -0700 From: engrsajjadsaf...@yahoo.com To: discuss-gnuradio@gnu.org Subject: [Discuss-gnuradio] Calculating the delay of TCP link. Hi,I am sending audio at 50 kHz sample rate via TCP sink from host A to other host B. The host B is connected via router in same network. How can i calculate the time delay from host A to host B via this TCP link. Best Regards,SAJJAD SAFDAR ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Calculating the delay of TCP link.
Hi, Is it any way to calculate using the MTU size of TCP packet and the sampling rate, like a mathematical approach using formulas. Best Regards, SAJJAD SAFDAR From: Mark McCarron mark.mccar...@live.co.uk To: Sajjad Safdar engrsajjadsaf...@yahoo.com Sent: Tuesday, April 30, 2013 12:33 AM Subject: RE: [Discuss-gnuradio] Calculating the delay of TCP link. Calculating delay is complex. If you just want to know the average time between hosts on an IP network, then use the Ping command. It has a RTT value in ms. Just remember that on a packet switched network, this can vary but is typically under 1ms in a local environment. Similar delays exist throughout the receive chain and processor, which are virtually impossible to measure accurately. Accurate measurements like for radar, or bearings are impossible without some form of time-stamp at the receiver and that would require an atomic clock chip. Regards, Mark McCarron Date: Mon, 29 Apr 2013 12:01:57 -0700 From: engrsajjadsaf...@yahoo.com To: discuss-gnuradio@gnu.org Subject: [Discuss-gnuradio] Calculating the delay of TCP link. Hi, I am sending audio at 50 kHz sample rate via TCP sink from host A to other host B. The host B is connected via router in same network. How can i calculate the time delay from host A to host B via this TCP link. Best Regards, SAJJAD SAFDAR ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Calculating the delay of TCP link.
On 04/30/2013 03:40 PM, Sajjad Safdar wrote: Hi, Is it any way to calculate using the MTU size of TCP packet and the sampling rate, like a mathematical approach using formulas. Best Regards, SAJJAD SAFDAR Well, no, because you have to actually *measure* the delay. Any real IP network has a number of components, each of which introduces time-varying latencies. It's a meaningless question to ask what is the delay of a typical TCP channel. Because, well, there's no such thing. Is your TCP channel across the room on a piece of wire? Does it go through switches/routers? How many of them? Are all the elements running at the same notional bit-rate? What is the current latency of packets from userland, through the kernel, until they hit the wire? That varies both with system architecture and current system loading factors. You could probably boil it all down to several different delay contributions, assign them variables and weighting, and come up with an equation. But without estimates for the likely ranges of each parameter, it won't tell you anything useful, compared to actually measuring the channel. Frequently. -- Marcus Leech Principal Investigator Shirleys Bay Radio Astronomy Consortium http://www.sbrac.org ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Calculating the delay of TCP link.
The MTU will only tell you if there is fragmentation. In packet switched networks, there can be delays for any number of reasons that are not entirely predictable. For example, assume someone is watching a video, using VOIP, downloading, etc. These can place heavy load on a switch, router or hub and saturate buffers delaying your packets and reducing throughput. Other factors such as QoS or traffic shaping can alter things. Then you have cosmic rays, bad wires, failing circuitry, etc. Then on a PC the network stack itself can be a source of delays as this is implemented in software a dependent on the scheduler and what else is happening in the machine. Trying to monitor all this, only places additional load on these systems a skews your results. The best you can do is attempt to define an average and identify the worst case scenario. Aiming between these two figures will normally provide you with a robust service that exceeds expectation. Regards, Mark McCarron Date: Tue, 30 Apr 2013 12:40:07 -0700 From: engrsajjadsaf...@yahoo.com Subject: Re: [Discuss-gnuradio] Calculating the delay of TCP link. To: mark.mccar...@live.co.uk Hi,Is it any way to calculate using the MTU size of TCP packet and the sampling rate, like a mathematical approach using formulas. Best Regards,SAJJAD SAFDAR From: Mark McCarron mark.mccar...@live.co.uk To: Sajjad Safdar engrsajjadsaf...@yahoo.com Sent: Tuesday, April 30, 2013 12:33 AM Subject: RE: [Discuss-gnuradio] Calculating the delay of TCP link. Calculating delay is complex. If you just want to know the average time between hosts on an IP network, then use the Ping command. It has a RTT value in ms. Just remember that on a packet switched network, this can vary but is typically under 1ms in a local environment. Similar delays exist throughout the receive chain and processor, which are virtually impossible to measure accurately. Accurate measurements like for radar, or bearings are impossible without some form of time-stamp at the receiver and that would require an atomic clock chip. Regards, Mark McCarron Date: Mon, 29 Apr 2013 12:01:57 -0700 From: engrsajjadsaf...@yahoo.com To: discuss-gnuradio@gnu.org Subject: [Discuss-gnuradio] Calculating the delay of TCP link. Hi,I am sending audio at 50 kHz sample rate via TCP sink from host A to other host B. The host B is connected via router in same network. How can i calculate the time delay from host A to host B via this TCP link. Best Regards,SAJJAD SAFDAR ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Calculating the delay of TCP link.
Hi Sajjad, Try tcping if ping doesn't do what you want: http://www.linuxco.de/tcping/tcping.html Mike -- Mike Jameson M0MIK BSc MIET Email: m...@scanoo.com Web: http://scanoo.com On 29 April 2013 20:01, Sajjad Safdar engrsajjadsaf...@yahoo.com wrote: Hi, I am sending audio at 50 kHz sample rate via TCP sink from host A to other host B. The host B is connected via router in same network. How can i calculate the time delay from host A to host B via this TCP link. Best Regards, SAJJAD SAFDAR ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] Calculating the delay of TCP link.
Hi Sajjad, Ignore the last message! TCP Traceroute is actually what you are after: http://michael.toren.net/code/tcptraceroute/ You will need to do a time to live of 1 Mike -- Mike Jameson M0MIK BSc MIET Email: m...@scanoo.com Web: http://scanoo.com On 29 April 2013 20:21, Mike Jameson m...@scanoo.com wrote: Hi Sajjad, Try tcping if ping doesn't do what you want: http://www.linuxco.de/tcping/tcping.html Mike -- Mike Jameson M0MIK BSc MIET Email: m...@scanoo.com Web: http://scanoo.com On 29 April 2013 20:01, Sajjad Safdar engrsajjadsaf...@yahoo.com wrote: Hi, I am sending audio at 50 kHz sample rate via TCP sink from host A to other host B. The host B is connected via router in same network. How can i calculate the time delay from host A to host B via this TCP link. Best Regards, SAJJAD SAFDAR ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
