Greets
I have been having an issues for a number of months now relating
to the ISP of a client.
The current situation is this:
The satellite offices of the client installed VOIP and have
had a ton!! of grief with it, not an uncommon story I'm sure.
The head office and and the primary satellite office are connected to
the ISP
through wireless.
The core router of the ISP is a Cisco 7200. The clients maximum
throughput has not
been an issue at any time. There is a 3-10 second "hesitation" in the
network
as the 7200 rehashes the routing tables, processor is at %100 during the
period as
stated by the ISP.
The ISP has stated that Cisco says this delay is normal for the routing
table reload.
Connections between the satellite offices will drop connections usually
during the
measured "hesitation" but not always. When the VOIP system was in place
during this
hesitation, and with active Citrix sessions, I have observed no
interruption in service
or voice hesitation. Even in off hours the session drops have been as
frequent as during
main business hours. I have often been dropped while doing remote
service via SSH to either
office location.
As the ISP has indicated, the method employed by the ISP to diagnose the
packet drop is "ping".
The VOIP system has dropped calls and is in the process of being replace
with the
original PSTN. The satellite offices are connected through OpenBSD 3.6
stable
IPSec tunnels. The VOIP was NOT running through the IPSec Tunnels at any
time.
With the VOIP system turned off there is no difference in the packet
loss graphs as
indicated by Ping Plotter ICMP mode. The Citrix sessions, whether or not
running through
the tunnels have the same packet loss, session dropping characteristics.
With only one Citrix client connected to the head office late at night
via Internet
there was packet loss whose timing matched the Citrix session.
I do not have direct access to the ISP equipment but have run a number
of end to
end tests with programs like pchar, hping etc., currently setting up a
smokeping
box to give an executive view of problems.
Using pchar as the example, the tests, there has been a couple dozen of
them have all
showed very similar results as shown below
Sincerely
Bob DeBolt
Pres / CEO
Starblanket Research
Calgary 280-3695
cell 560-1202
1-877-280-3695
bob.debolt@xxxxxxxxxxxxxx