384k Partial T1 Hub

[Synthetic]

Currently we have a 384kbit partial T1, and I notice that while I'm in a game, and someone starts to download something my ping goes crazy, spiking from 20-200. Anyway, would getting a switch help this? Currently we are using a hub and I don't know if that is the cause of the problem or not.

Thanks

 

[Garion]

Nope - You're just seeing the effect of a small Internet pipe - When it gets saturated, it takes a while to queue up all the requests, hence the large ping times. Nothing you can do, short of upgrading the circuit will make any difference.

- G

 

[Synthetic]

Originally posted by: Garion
Nope - You're just seeing the effect of a small Internet pipe - When it gets saturated, it takes a while to queue up all the requests, hence the large ping times. Nothing you can do, short of upgrading the circuit will make any difference.

- G

So there is no distinct advantage in my case if I upgrade to a switch?

I guess I don't understand why this doesn't happen on say, 1.5/128 cable. How is that a different situation? With the bigger pipe the user that is downloading is also downloading at a faster speed.

We are planning on upgrading to a full T1, but we just want to make sure that users downloading will not have a negative effect on ping times and such.

 

[ITJunkie]

Question 1) there is no real advantage in this case. Spend the money elsewhere, follow Garion's advice and upgrade the circuit.

Question 2) It's because your 1.5/128 is roughly 4 times faster. Think of it this way...here is the size of your 384K pipe "o" (data flowing through the "o") and here is the size of your 1.5Mb pipe "O".

Does that help make some sense of it?

 

[Synthetic]

Originally posted by: ITJunkie
Question 1) there is no real advantage in this case. Spend the money elsewhere, follow Garion's advice and upgrade the circuit.

Question 2) It's because your 1.5/128 is roughly 4 times faster. Think of it this way...here is the size of your 384K pipe "o" (data flowing through the "o") and here is the size of your 1.5Mb pipe "O".

Does that help make some sense of it?

I understand the pipe size analogy....... reread my question, is the download speed not proportional?? Is it not filling up the same fraction of the pipe? That was my question.

And we just upgraded to a Full T1 today

 

[Garion]

Ping is depedent on a combination of upload speed (you sending the ping out) and download speed (it coming back). It's possible that your 384K circuit is getting *totally* saturated with the download and you can't get the response back quickly. Cable modems typically have a *lot* more overhead to allow multiple kinds of traffic to sneak through.

The place you really see poor network performance on a cable modem is when there's a large UPLOAD going on. That taps out the relative small upload bandwith and your pings get slowed down on the outbound leg.

With a full T1, you're going to see much better performance and pesky business use won't interrupt your gaming quite so much.

- G

 

[Synthetic]

Nope.

Just like I thought, same problem with the full.

The first set of ping times are with nothing downloading, second set is with downloading.

>ping google.com

Pinging google.com [216.239.53.100] with 32 bytes of data:

Reply from 216.239.53.100: bytes=32 time=74ms TTL=51
Reply from 216.239.53.100: bytes=32 time=69ms TTL=51
Reply from 216.239.53.100: bytes=32 time=67ms TTL=51
Reply from 216.239.53.100: bytes=32 time=82ms TTL=51

Ping statistics for 216.239.53.100:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 67ms, Maximum = 82ms, Average = 73ms

>ping google.com

Pinging google.com [216.239.53.100] with 32 bytes of data:

Reply from 216.239.53.100: bytes=32 time=442ms TTL=51
Reply from 216.239.53.100: bytes=32 time=520ms TTL=51
Request timed out.
Reply from 216.239.53.100: bytes=32 time=374ms TTL=51

Ping statistics for 216.239.53.100:
Packets: Sent = 4, Received = 3, Lost = 1 (25% loss),
Approximate round trip times in milli-seconds:
Minimum = 374ms, Maximum = 520ms, Average = 445ms

edit: Got the answer from someone on another forum:

One thing to keep in mind is that "ping" packets are very low on the priority totem-pole of TCP/IP traffic. If a download or other higher-priority traffic is in progress, pings get shuffled to the bottom of the stack and hence you end up with poor return times.

Checked in game pingtimes in game and they were fine.

 

[jonmullen]

A way to get rid off this effect is to setup a router with QoS services. I just finished builiding a linux machine for this exact purpose