WOW.. That is the most complicated Ping I have ever seen.. :) <br><br>This is the result I got. <br><br># ping -f -i .02 -s 180 -Q 0xb8 xx.xx.xx.xx<br><i>PING xx.xx.xx.xx (xx.xx.xx.xx) 180(208) bytes of data.<br>.............<br>
--- xx.xx.xx.xx ping statistics ---<br>15338 packets transmitted, 15325 received, 0% packet loss, time 352748ms<br>rtt min/avg/max/mdev = 276.499/286.185/310.118/7.248 ms, pipe 15, ipg/ewma 22.999/284.882 ms<br></i><br><br>
The same test with my Present SIP Provider gave me the result below. <br><br><i>10926 packets transmitted, 10913 received, 0% packet loss, time 244048ms<br>rtt min/avg/max/mdev = 289.514/292.668/316.350/2.336 ms, pipe 15, ipg/ewma 22.338/292.941 ms<br>
</i><br><br>I suppose the value of mdev is much higher in the first case but 0% packet loss in both the cases. <br>Does this mean that the voice quality is going to be real bad?? <br><br>Thanks,<br>Najim<br><br><div class="gmail_quote">
On Thu, Dec 1, 2011 at 6:33 AM, Adam Moffett <span dir="ltr"><<a href="mailto:adamlists@plexicomm.net">adamlists@plexicomm.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div class="im"><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
a ping is the time a packet needs for travelling to a destination and<br>
back to you. So the one way latency you are refering to, should be half<br>
the time your ping took.<br>
<br>
In your case this will be 130ms, I would say this is still reasonable.<br>
</blockquote></blockquote></div>
I am probably splitting hairs, but that's not always true because there's no guarantee that the reply traveled the same path as the echo request. If you dig into BGP issues you'll see sometimes that traffic one direction takes a different route than traffic the other direction. I don't know of any simple and accurate way to learn the "one way" latency so I'm surprised they specified anything other than round trip time.<div class="im">
<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
'Ping time' is not an accurate predictor of SIP quality.<br>
<br>
A 'ping' is an ICMP Echo/reply packet and some routers consider them less important than 'data' packets and service them on an 'as resources permit' basis. <br>
</blockquote></div>
That's possibly maybe true if someone's router or connection is overloaded and they are trying to make up for it with CoS policies while they save up for an upgrade. Otherwise it's an apology for a crappy network. That's the brutally honest truth.<br>
<br>
You can make a pretty good prediction with ping.<br>
"sudo ping -f -i .02 -s 180 -Q 0xb8 [ip]" gives a tolerable simulation of voip traffic. let it run for awhile, then press ctrl+c and see how many packets were dropped and also check the mdev number. If mdev is low and packet loss is almost nothing then you can expect decent voice quality. It may not be a 100% perfect test, but I'll bet you a vast majority of the time I can do that test and tell you whether it's going to suck.<br>
<br>
latency by itself with low jitter and no packet loss just means delay. It's a matter of opinion and circumstance how tolerable delay is, but I think your 230ms ping is at the upper edge of what most people can live with. Much more than that and you'll be tempted to say 'over' at the end of sentence.<div class="HOEnZb">
<div class="h5"><br>
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