Ping (latency) versus bandwidth

Submitted by kiddcreole99 on Sun, 07/19/2009 - 8:27am

I am a network engineer and here is the best analogy I can give you to help understand the difference between latency and bandwidth and why more bandwidth may not affect latency.

<analogy>

If you are driving from New York to Los Angelos, maintain posted speed limits, and there is no other traffic on the roads (don't we wish!!), it will still take you as long to get there (latency) regardless of whether you are driving on a 8-lane interstate highway (high bandwidth) or a 2-lane state highway (low bandwidth).

The times when the interstate helps is when there is lot of other traffic (bit torrents, streaming video, etc) that would slow you down from maintaining the posted speed limit on the 2-lane highway. You can move more cars (data) at the posted speed limit on a 8-lane interstate than you can on a 2-lane state highway.  

</analogy>

The statement that you you will always get better ping from a server 50 miles from your house than the one 1000 miles away is a little bit of a misstatement. While odds are higher that will be the case, that's not a definite. A lot of that could depend on the ISP of site hosting the server and your ISP. For (hypothetical) example, if my ISP is AT&T and the server is at a location that has Comcast/Mediacomm/other cable provider, it is very possible that the way AT&T routes my data may send me from New York to Atlanta, to Miami, to Chicago, back to New York, 50 miles away from my house to the server, because that is the path it knows to take to get out of the AT&T network and on to the cable provider network. Internet traffic traverses a large collection of routers to get your data where you want it to go.

 

As a helpful tip, if you want to determine where your latency is coming from and what path your data takes to get where it's going, use the "traceroute" tool within Windows command line to watch the path your traffic takes as well as three average response times from each hop it takes to get from point A to point B. The context to use from the command prompt is "tracert <domain name or IP address>", for example, "tracert maximumpc.com". This won't really fix the problem, but at least you will know where the slowdown is happening. 

I sympathize with your problem. I have had issues playing some Xbox360 games with friends using Xlink Kai. Latency just won't allow them to play. 

As stated in the article, there are many factors that affect latency. From the sounds of it, bandwidth is not a reason for yours, therefore QoS won't fix the problem either. QoS "reserves" some of your available bandwidth for a specified purpose (VoIP, gaming, etc), but if bandwidth isn't a problem (which I think we've already determined), then QoS will have no impact.

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Ping

Submitted by chrisv815 on Wed, 07/15/2009 - 1:19pm

I have been very confused by my ping for some time now.

I have the fastest computer in my house.  Its not blazing but its good.  Phenom quad core 9950 black 4GB RAM,   900GB 4 disk Raid5 array , nvidia 9800GTX+ overclock ed.  on an ASUS M3N-HT deluxe Mobo.  This is connected to my router with a 3ft. ethernet cable.  and I am using vista 32bit.

Problem is I am getting 250ms pings on World of warcraft.  The other 6 computers in my house are getting below 200ms and in some cases below 100ms.   some are connecting over wifi some are using ethernet cables as long as 100ft.  all into the same router but mine is the closest to the router. They are  on various OS's from XP to win2000pro.  with as little as 1GB RAM and AMD1800 procs on some.  

Why would the best rig be getting such crappy ping times?  And yes I swapped the cable several times.

Everything else is fine I get over 100FPS on a 24" LCD with all eye candy up.   

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Submitted by bose2009 on Tue, 07/14/2009 - 5:42pm

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QOS ??????? QOS does

Submitted by IFLATLINEI on Tue, 07/14/2009 - 1:57pm

QOS ???????

QOS does absolutley nothing unless your for instance you downloading torrents on another computer. Its a way for the router to determine whats important by you setting it. Even then its a crapshoot. Dont rely on junk like that. Just dont run anything else while gaming period.

Besides the OP needs to know that by improving his connection all hes doing is making sure he gets shot. While others (usually half of gamers, atleast) because of crappy ISP packages or by running wireless dont get hit because your rounds dont ever get to them.

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lower ping ups your pwng

Submitted by rjzdanis on Tue, 07/14/2009 - 1:46pm

I don't know if this applies to COD4 but when I play UT3, I first look for the ping on the server I'm aiming to play on.  If the ping is too high, I'll refresh the server choices until a lower ping is displayed.  Once I see a ping I can live with I join the server.  That seems to work for me.

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Fast Path

Submitted by LVmonkey on Tue, 07/14/2009 - 5:48am

I've heard a number people speak of getting a "Fast Path" connection, as oppossed to "interleave". I work for a major US ISP and have seen the requests quite often. It does seem to trick the ping counters but generally is a bad idea.

ISP's tend to stick you too fast path if your connection can handle it (through everything through the PVC), but the way that it improves latency is to drop a lot of error checking and correcting... so your latency drops but so does the number of good packs being sent... so end of day, ends up a worse connection that looks better (due to the latency of the packets making it through).

 ...google the terms to see what i mean, if your curious...

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People do not understand the

Submitted by Digital-Storm on Tue, 07/14/2009 - 4:54am

People do not understand how ping gets calculated. If doesn't matter if you get a faster connection with ISP A. Your ping will not change because your packets are still going through the same servers.

 

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Woe Is Me

Submitted by mclovin on Mon, 07/13/2009 - 10:34pm

This post peaked my interest, because I'm an avid online gamer who had to move to Guam for my job. Guam is directly in between Japan and Australia. My ping is now a solid 350 ms in World of Warcraft, and 200 ms in Team Fortress 2. What a bummer, man, it feels like I'm back in the 90's. Unfortunately, the other players are not....

Fact: Australian servers are actually slower than East Coast US. Weird!

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Phone Line Condition?

Submitted by nsvander on Mon, 07/13/2009 - 4:58pm

The thing people forget about is the condition of there home phone lines, if they are old and have been in the house since it was built (in my they were 35 years old) replace them.  The old lines where not designed to handle data, and are not UTP. Try moving to a different phone outlet, or replacing the lines with Cat5E and you will lower your ping a little too.

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A lot of people seem to be

Submitted by I Jedi on Mon, 07/13/2009 - 3:51pm

A lot of people seem to be uneducated and surround themselves with the idea that the better connection they have, the faster the web will always be. While this definitely holds true when comparing dial-up to broadband, there is always a certain point where you won't get to download files that much faster. A lot of servers cap their max. download rates at 800/Kbps. Though, recently, I've seen some networks I download from start to have a megabyte and a bit over, which is awesome.

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