Re: 7845i keeps dropping IP connection

[Jim <alarminex@xxxxxxx>]

On Oct 22, 9:53=A0pm, "Petem" <petem...@xxxxxxxxx> wrote:
> "Jim" =A0a =E9crit dans le message de groupe de discussion :
> d930cf88-047c-4940-9511-e53277a46...@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> > Sometimes you'll find that there's just "something" about a particular
> > router that doesn't jive with something on YOUR network but will work
> > without a hitch on another network with different components. =A0 =A0Go
> > figure!
>
> Totally true, had once a big argument with a network specialist...or so..=
.
> telling him that his 3com switch had a non compatible auto negociate with=
 my
> DVR so I could not connect it directly to his switch, the only way to mak=
e
> it work was if I used a small switch (d-link 4 port) between the dvr and
> 3com switch.
>
> the dvr was setup to 100mb full duplex and the switch was allways detecti=
ng
> the dvr as 10mb full duplex.. damn it was hell to make him understand tha=
t
> autonegociate doesnt allways work..after 3 days of email and visit on sit=
e
> (he didnt want the dlink switch to stay there) he finally reprogram the p=
ort
> on the switch to be fix at 100mb full duplex..all was well after that..
>
> One other time a customer was using a small network ionterface from dsc t=
o
> do local =A0and outside download for a pc4020 and dsl3 for user..
>
> the customer was complaining that he was not able to connect to the devic=
e
> during the day.. just at night..
> That was very strange.. On site I pluged my laptop and started sniffing t=
he
> packet on the network cable that was going to the device..there was about
> 30mb/s of broadcast packet going to every computer on the network(broadca=
st
> packet are data sent to all device on a network...) But the catch was tha=
t
> the device was a 10mb/s half duplex old thing.. try to send 30,b/s to a
> 10mb/s device you will overload it and you wont be able to communicate wi=
th
> it..
> The network guys told me that it was impossible to have that much broadca=
st
> on there network. so I made them download ethereal (now wireshark) and th=
ey
> were not knowledgable enough to understand what there were looking at..
>
> I had to bring from the shop a laptop I used to debug real nasty problem =
on
> network that had computer associate port sniffer ( A damn good program bu=
t a
> bit pricey) then with a pie chart diagram of the packet received on that
> computer for 10 minute they did understood the obvious..
>
> Know what was all this broadcast stuff.. Radio station.. 5 or 6 people we=
re
> listening to some radio station over the internet..all different one. Use=
ly
> it should not have created any problem. But here there proxy server for t=
he
> network were converting Unicast packets to broadcast packets...(Unicast i=
s a
> way to send only one packets over internet and have it restransmit to eve=
ry
> one at once that ask for it..so radio station dont have to send there dat=
a
> to 30000 pople at once (think of the bandwith needed for that!!!)
>
> So networking is a strange world.. anything and the inverse can happen an=
d
> you need some really good alarm tech to understand it..

Sounds like you get into it a lot deeper than I do.

I'm more of a trial and error trouble shooter and if I can't figure it
out, call the manufacturer tech line. Only do residential and small
business simple network setups. Router, maybe a switch or two, a few
computers. I've networked a couple of home automation/whole house
audio/video systems.  Always setting up from scratch so there's not
much trouble shooting to do. Most of what I do works the first time so
I must be doing something right.