Tracers-packets lost question

[tobylee]

Anyone who is aware of my problems on terra... how many screenshots should I send in to PowWeb? I have 4 right now.
Thanks. All show packets being lost - I got email telling me to send in screenshots, but no mention of how many!

[RSaucier]

Hi TL,

If terra is showing consistent packet loss at terra, those are the ones you should send. Ones that just show routers between you and terra losing packets should be ignored -- PowWeb can't do anything about those.

'Zat help?

Robert

[tobylee]

oooooooooohhhh... ok. Now I get it. Nothing is being lost at terra. What about the one's being lost in the middle of the route of 20 hops. Sort of a consistent 10-20% at several hops in the middle? Not important??? Are packets picked up that are dropped? First time I've ever paid attention to monitoring this. Thanks Robert!

[RSaucier]

TL,

If the samples you had up the other day are representative, it looks like Genuity is the one having problems.

You can call your ISPs support group and see if they can change any of their routing to avoid those network segments or if they can pass along a service request to Genuity.

Packets that are dropped just disappear. I know it's cliche, but think of the Internet as a road.

This road is built of layers that allow cars (packets) to get from the factory to the car lot. Now, the factory can send cars out in any order but the car lot can only sell them in numeric order.

(hang with me here)

Now, these cars are efficient but about as robust as wet toilet tissue. If they hit a pot-hole, they fall apart.

The car lot calls the factory and lets them know that car 234 didn't make it, can then send another with exactly the same features. The factory sends an exact duplicate of car 234.

If the clones of car 234 keep hitting the pot-hole and disappearing, the factory will tell the drivers to take a different route. Eventually, car 234 makes it to the lot and sales can continue.

The cars are more or less defined by the HyperText Transfer Protocol (the http in a website address). The process that allows the cars to get from the factory to the lot is the Transmission Control Protocol/Internet Protocol (TCP/IP).

In an application that uses TCP/IP, if a packet (car) doesn't make it to the sales lot (browser -or- server), a request is sent for that packet to be resent. These packets can only be reassembled in the order they were disassembled, so one missing packet can really screw things up.

It's the dropped packets, request for resend and resending process that can really slow things down.

Okay, it was a 4-mile high view that jumped around all over the place but I hope it made sense and that it helped. :)

Robert

[tobylee]

Robert... That was very easy to understand. I appreciate your taking the time to explain it to me. You done good! TY!:)

[RSaucier]

Whew! I was afraid I was starting to ramble too much! Glad it helped a little!

Robert