Hi Chris,
Perhaps it's a perception problem...but I've been noticing some pretty tough
times on my VOIP phone as well, and I'm wondering where it's coming from.
Do you have an alternative test I can use and show my customers? They're
going to use ping, and not be happy with the apparent result.
Norm
----- Original Message -----
From: "Chris Conn" <cconn@abacom.com>
To: "Karlnet Mailing List" <karlnet@WISPNotes.com>
Sent: Thursday, September 11, 2003 9:18 AM
Subject: Re: [Karlnet] RE: Ping Jitter
> Hello,
>
> I find it curious that people use ICMP rtt to measure anything. This is
even
> flawed in tradition land-based networking for various reasons, however
compound
> the fact that the Karlnet polling algorithm is designed to maximize
throughput
> to satellites who need airtime can easily explain this "jitter" as you
call it.
> If you even moderately load the satellites with traffic, the ICMP rtt
times
> stabilize greatly. I have not corrolated this phenomenon to be associated
to
> lower SNR values, however I have easily seen this on my own networks.
>
> It is not too difficult to explain that appearances can be deceiving.
ICMP rtt
> is not a bandwith measurement tool, it is a REACHABILITY tool. I can
> understand that if your ICMP rtt is 1000+ms constantly there may be an
issue
> either of bandwith saturation or other (retransmits on your lower SNR
> satellites???), but if it jumps from 30 to 250 momentarily, this does not
> represent lack of bandwith, especially when you take into consideration
again
> the polling mechanism.
>
> So, would you rather have a network that _seems_ to have low latency, or
do you
> truly want to maximize what little spectrum can be used to carry data from
and
> to satellites that need it? It may be difficult to explain to a clueless
> customer that uses whatever el-cheapo network analysis tool ala-Net.Medic,
> however I think it should be understood by the network operator to at
least be
> able to attempt to explain this to the customer.
>
> My 0.02$,
>
> Chris
>
>
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