Expert networker ROSEMARY HATTERSLEY explains how to speed up wired and wireless
networks, identify and manage bottlenecks and get everything running like clockwork Network like a pro Not being able to get online is an incredibly frustrating situation, as we've discovered here at PCA Towers during recent losses of web access and network connectivity. It's all very well taking a laptop to a nearby coffee shop, where the Wi-Fi is free and the beans freshly roasted, but who's to say how secure that wireless connection really is? Other network problems arise in the office. While one employee is taking part in a webcast or streaming a video clip, everyone else may find their web connection clunky. Even Spotify and online radio stations can affect office network performance. Similar issues occur at home. That all-you-caneat broadband connection suddenly seems less impressive - and gets a lot slower - when Mum's making a Skype call to a friend, Dad's checking his Fantasy Football team and the kids are instant-messaging their mates. And it doesn't help if the technology needed to deliver it all is prone to flakiness, or if the hardware or network software limits the bandwidth. We look at how to deal with some of these problems over the following pages. There are several ways to speed up your home network. First is to upgrade from an older 802.11b/g network to one that supports the latest, much faster wireless-n standard. This is able to offer wireless video and music streaming - ideal if you want to use a feature such as Windows 7's Play To function. Laptops, network media drivers and peripherals such as printers that support this protocol are now available. You'll need a suitable router to provide the additional bandwidth, but prices are already competitive. It took almost two years for the standard to be ratified, and many manufacturers brought out 'draft-n' products that are firmware-upgradable. Office users aren't quite so lucky. The cost of upgrading the network infrastructure is likely to be prohibitive, so a fatter pipe or faster network switch won't necessarily cure the symptoms. Instead, you may have to look at what's causing the bottlenecks in the first place. Once you've identified the traffic hold-ups and resource hogs, you can limit their video streaming to after hours or prioritise email traffic instead. SPEED UP YOUR NETWORK START Network slowdowns can be tricky to troubleshoot. Much depends on what you're using the network for; copying files to another system might slow to a crawl if you're writing to a NAS device attached to an old PC. However, a few general tweaks and tricks can boost your network performance in Windows. 2 Check your PC's connection status. In XP, go to Start, Connect To and view all connections. In Vista and Windows 7, type network connection into the search field. You should also run the troubleshooting wizard and install any new Windows updates ( update.microsoft.com) and the latest drivers for your network cards. 3 Next, check your router firmware is up to date; updates often provide performance improvements and smooth out glitches. Check for updates at the router manufacturer's website and initiate the firmware update using your router's web administration panel. This could produce a noticeable speed boost. 4 Windows 7 features a dedicated Network and Sharing Center where you can get an overview of your system's wireless connection status, see a map of connected devices - a potentially useful feature that could help you quickly identify which one is sucking all the bandwidth - and initiate a troubleshooter. 5 Now try adjusting the network card's auto-negotiating setting. In the Control Panel, click Network and Sharing Center, Change Adapter Settings, then right-click on your Local Area Connection and select Properties. Go to the Connect Using field and tick Configure. Select Advanced. Set 'Speed & Duplex' to its highest available setting. 6 Vista often throttles your network connection when playing movies. To adjust this, press Windows, R, type regedit, Enter. In the Registry Editor, navigate to the Hkey_Local_Machine\Software\ Microsoft\WindowsNT\CurrentVersion\Multimedia\SystemProfile key. Enter a higher decimal value under 'NetworkThrottlingIndex'. J USEFUL DOWNLOADS Advanced IP Scanner 1.5 For a quick, no-fuss way to view all the devices on your network, along with their IP addresses and other information, give this small, free, simple utility a try. It performs a lightning-fast scan of all IP addresses on your network, or of all devices in an IP range you specify, then tells you what devices are at what address, and whether each device is live or idle. It also provides each device's status, machine name, NetBIOS information, ping information and MAC address. Also included are a few other useful tools, such as the ability to shut down PCs remotely. And the Wake-on-LAN feature can wake PCs containing network cards that support the capability. radmin.com Paglo Crawler/GoToManage Windows 7 shows you lots of information about what's part of your network, its status, what else it's connected to and whether it's in active use. Previous versions of Windows are less forthcoming. Paglo Crawler (recently relaunched as GoToManage) crawls your network, identifies every device, and gives you thorough information about each. It isn't especially easy to use but, if you know your way around a network, you'll appreciate the level of detail. For example, for each device you'll be able to view the NetBios name, the DNS information, the network subnet and even port numbers. paglo.com/product DIAGNOSE NETWORK BOTTLENECKS Ethernet networks can run without any problems for a long time. But a disaster can occur without warning, debilitating an underequipped network. One danger is a broadcast storm, in which a defective or misconfigured network device forces your network to shut down by flooding it with traffic. A malware-infected computer that sends a barrage of email or tries to replicate to computers on the network or internet is another potential headache. As well as slowing down everything on the network, it's likely to create friction with your ISP. Another common complaint is resource-hungry users, applications or services using up all the bandwidth to stream video or download huge files. Identify the problems Wireshark ( wireshark.org) is a user-friendly freeware tool that allows you to identify bandwidth hogs. It can also warn you of an email account that's barraging others with messages, suggesting a possible malware infestation. The tool captures network packets, analyses them and displays detailed packet data. Download the version you need from the site. When you run the program (the file is approximately 77MB) you may be prompted to install WinCap at the same time. Click the 'What is WinCap?' button for details of its functions. Now you need to identify the traffic you're monitoring. Plug a PC running Wireshark into any available switch port and you'll see only traffic to and from your system and broadcast/multicast traffic - interesting, but not always useful. To monitor traffic from an ethernet port other than the one your PC is plugged into, you need to mirror your ports. You may want to check on the port for your internet connection, for example. Consult your router documentation for specifics; there may be a simple browser interface to do so, as there was on our 24-port Netgear switch. Next, let's capture some network traffic. Click Capture, Options and select the correct interface; to focus on a specific type of traffic, choose Capture Filter and select or create a filter. You can specify a time period or amount of data Wireshark should collect by ticking the appropriate Stop Capture box and select a suitable drop-down menu value. If you let Wireshark run for an extended period of time, file sizes can become unmanageably large. Now click Start, and you'll see traffic flowing in real time. Press Stop to automatically cease data capture. Now you need to interpret the data. If you're investigating a network slowdown, you'll want to pinpoint the source of traffic. Choose Statistics, Conversations and select the IPv4 tab; from there, you can sort by such criteria as 'Bytes' (to pinpoint a PC that's generating too much traffic). To search for a particular type of traffic, click Analyze, 'Enabled protocols', and tick the protocols you want. Traffic-analysis alternatives Wireshark is a flexible tool for locating network problems and analysing your traffic. It can be a handful at first, but is well worth learning to wield properly. Another open-source option is NetworkActiv PIAFCTM ( bit.ly/bLD3dI). This content-management tool works on the same principle, mirroring the port where traffic enters the network from outside and identifying unacceptably large files. It allows you to search for offending files by type and then drill down to see who has been flouting the office acceptable-use policy. J Michael Scalisi CREATE A WI-FI HOTSPOT WITH CONNECTIFY A few months before Microsoft launched Windows 7, eagle-eyed developers noticed an incomplete bit of code that allowed users to connect with each other on an ad-hoc basis. The feature in the final version of Windows 7 is HomeGroups and allows pre-approved sets of users to connect and share content without having to negotiate tricky network protocols. Connectify (connectify.me) is based on the same principle, and allows a Windows 7 user to turn their laptop into a hotspot that others can use. Developer Gizis suggests the use of a wireless printer without any setup. Another scenario allows a smartphone user to use the Wi-Fi connection rather than their 3G or Edge data allowance. What's useful is that, while Connectify requires a Windows 7 PC as the host, any Wi-Fienabled laptop (Windows, Linux or Mac) can use the hotspot without installing any software. BANISH WIRELESS BLUES START Wireless networks have got faster but can still go wrong. And if your network's down, so is your web access. PCs and laptops have ethernet ports, so can be added to a wired network; each system simply needs an NIC (network interface card), and the 'server' machine must be connected to the router. 2 If your router has a Quality of Service (QoS) feature, use this to make clearer Skype calls without the voice dropouts and scrambling you'd otherwise get on a congested network. QoS options are often found in the Settings menu on the configuration and administration panes. Consult the router manual for details. 3 Another way around wireless woes is to switch to a different sort of network, at least for the most important elements of the network. HomePlugs (also known as powerline plugs) use the electrical circuit in the building to form a physical network. You need to have pairs of HomePlugs of the same type, however. 4 If a device disappears from the network or can no longer get online, you may need to release its IP address and generate a new one. Go to Start, Run and type cmd. In the black screen that appears, type ipconfig/renew. Assuming you aren't using a static IP address, Windows should provide a new IP address. 5 The useful thing about phones and laptops with multiple connection options is that, if you can't get one type of coverage, you've got a fallback option. If you can't get 3G, find an internet cafe and search at your wireless provider's site for local options, or switch to the more widely supported and cheaper Wi-Fi. 6 If you've got a patchy wireless network, consider moving the router or replacing its antennae with high-gain ones - remember that routers can be impeded by thick walls. If this doesn't work, a booster may help. You can buy or make an aluminium cone that intensifies the signal ( cantenna.com). Technical telepathy: 09969636745 Saints are not always saints; sinners are not always sinners. Voice your thoughts in the blog to discuss the Rights of persons with disability bill at: http://www.accessindia.org.in/harish/blog.htm To unsubscribe send a message to [email protected] with the subject unsubscribe. To change your subscription to digest mode or make any other changes, please visit the list home page at http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in
