What's wrong with my Internet connection?
Summary Description The Internet is slow, you hate your ISP and your modem sucks! 5 Minute Guides takes you through the reasons for poor Internet performance.
Author

Publication

Roullas Top10 Simon Vandore

Newswire
No


Editorial InformationArticle Location http://www.newswire.com.au/0004/5mg27.htm
Article Topic 5 Minute Guides
Story Order
Story Group 000430
Post Date 27/04/2000 09:19 AM Status Posted Entered by Simon Vandore on 26/04/2000 11:41 AM


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The Internet is so slow. I hate my ISP and my modem sucks!
OK, but think twice before you call the support hotline. ISPs sometimes let their customers down, but there are many possible reasons for Internet slowdowns and it's usually possible for an informed Internet user to pinpoint the problem. But first, you need to understand everything that exists between you and the sites you access.
It's a 'thigh bone's connected to the knee bone' situation. Your computer's modem sends and receives data by establishing a connection to another modem that serves your ISP's computers. The ISP's internal network is connected to a 'backbone', a major artery of the Internet, which is connected to other backbones and international links. Data travelling between your computer and other Internet sites passes through routers, which are purpose-built computers that read the header information on data packets to direct traffic. Somewhere on one of the Internet's backbones, the site you're trying to access is connected in a similar fashion.
What types of problems can occur?
Let's start at the thigh bone again. A program or port setting might be affecting resources on your computer, or if you are connected to your ISP over the telephone lines, it may be the vagaries of the copper wire telephone system. Line noise and the way your telephone line is connected can affect the maximum speed and reliability that a modem can achieve. Rural users are sometimes unable to get more than a 9,600bps or 14.4Kbps connection, due either to outdated phone lines or the use of wireless technology to connect to the telephone exchange.
ISPs are to blame if their internal network equipment cannot cope with the load placed on it by their subscribers. They need to have fast enough servers, networks and enough bandwidth to the rest of the Internet for their subscribers to share without bogging everything down at peak times. Often a cheap ISP will have poor performance in the evening, and great performance in the early morning, simply due to the number of its subscribers who are online at the time; this can also be true of the Internet in Australia as a whole.
Often the problem lies somewhere between your ISP and the site you are trying to access. This is neither your ISP's fault nor the site's fault; rather, something somewhere on the Internet between them is to blame. Major routers do sometimes go haywire and it takes time to fix them. A good ISP will keep its users informed of trouble elsewhere on the Internet, perhaps on some kind of 'network status' Web page, particularly if there a scheduled downtime has been planned and announced by one of the backbone providers. The worst-case scenario is if the backbone to which your ISP is connected starts having regular problems. For example, the two major backbone providers in Australia are Telstra and Optus, and most ISPs buy bandwidth from them. In turn, they are connected to backbone providers in other countries, such as UUNet in the US.
Finally, it could be that the site you want to access is down. You can usually find this out by using the ping command.
What is this "ping"?
Ping is a basic TCP/IP command which bounces a tiny packet of information off a targeted Internet site and tells you the time it took in milliseconds. It's useful for finding out whether a site is reachable, and for finding out how much timelag there is between it and your computer. Note that some sites cannot be pinged, as a security measure, but most can.
To ping www.newswire.com.au, open an MS-DOS window and type 'ping newswire.com.au' (without the quotation marks) then hit enter. If you use Linux or another Unix variant, the command is the same. The default setting is for 5 ping packets to be sent, but if you just type 'ping' without an address, you will be shown a list of parameters which can change the way you use ping (for example 'ping newswire.com.au -t' will keep pinging indefinitely until you press Ctrl-C to stop it). On a modem connection, a healthy ping time will be between 150ms and 300ms to an Australian site, and 300ms to 500ms to an overseas site. Anything over about 800ms feels sluggish.
Ping also shows what is known as 'packet loss' -- the percentage of data that goes missing. If you send 100 ping packets (a reasonably good sample size) you should get 100 results. But you might find that 30 go missing, no matter which site you ping, which could mean you have 30% packet loss (particularly if this happens with all sites pinged). Ping packets are given lower priority by routers than HTTP or FTP packets, so this only gives you a clue as to the problem, but high ping packet loss generally means poor performance across the Internet. You might find high packet loss to overseas sites and low packet loss to Australian sites, which generally means there is congestion on international links. You can pinpoint the problem with traceroute.
Trace what?
Traceroute! This is absolutely the best tool for tracking down Internet problems between your PC and the site you want to access. Traceroute is related to ping, but it traces the journey your data must make across all the routers between you and the other site. It gives some ping results, but it also shows the IP number and usually the host name of each router or site. This is where it gets interesting, because if there is a hold-up, traceroute will return all the numbers and names up to the problem area, and then show asterisks instead of the problem router or site.
To perform a traceroute to www.newswire.com.au, open an MS-DOS window and type 'tracert newswire.com.au' (without the quotation marks) then hit enter. In Linux and other Unix variants, the command is 'traceroute'. Watch as the sites and routers are slowly identified and traced, starting with the ones nearest you, and leading right up to the targeted site. Note that some sites cannot be reached via traceroute, as a security measure, but all the hops leading to them can still be traced until the asterisks start.
To understand traceroute results, you need to read the Internet host names and numbers properly. For example, you will be able to see 'telstra.net' or 'optus.net' at the end of some of the host names, letting you know that the host is within Telstra's or Optus' network. If you are tracing overseas sites, you will see the names of overseas backbones and ISPs at the end of the host names. You can usually figure these out with an educated guess, or by looking at the country codes such as .au or .nz on them. If the host name is not resolved and you see an IP number instead (such as 203.4.212.10), a well-informed user can still tell something about the router or host: for example, an IP address beginning with 203 usually means the site is in Australia.
Another concern is the number of 'hops' that your traceroute shows the data making in order to reach its destination. The more hops along the way, the more likely it is that you will experience lag. For example, it might take five hops to reach an Australian site and 20 hops to reach a site in Brazil. And if one part of the Internet is down, the nature of TCP/IP networking is that the routers will try to find another route to the site you wish to access. This may increase the number of hops and add to congestion on routers, but you should still get what you were after.


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Bulletin SummaryWhat's wrong with my Internet connection?
The Internet is slow, you hate your ISP and your modem sucks! Newswire takes a 5-minute guide through the ins and outs of the Internet and examines other reasons for poor Internet performance.

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5-Minute Guide: What's wrong with my Internet connection?

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