FAQs

General

Can I detach the Xwire router's antennas and replace them?
In order to maintain the connection between the antenna and the connector, we intentionally designed the mechanism so that it is difficult to remove the antenna. The repeated separation action may be harmful to the equipment and have adverse reactions on connections. Frequently separating the antennas from the router end is not recommended. The antenna connector is a reverse SMA style connector.
 
Can multiple gamers on the LAN get on one game server and play simultaneously with just one public IP address?
It depends on which network game or type of game server you are using. For example, Unreal Tournament supports multi-login with one public IP.
 
Can the Router act as my DHCP server?
Yes. DHCP server software is built into the router.
 
Can the signal penetrate walls and buildings?
Yes, the signal can pass through walls and buildings, depending on what the wall is made of or what is in the wall. Walls with sheet metal covering may reflect the signals, so the radio waves will not penetrate it. Also walls with lots of wiring and poor wiring insulation may cause interference and degradation of signal, and hence, poor performance.
 
Does the Xwire router act as a gateway or as an access point?
In most cases, the Xwire Router is a bridge and allows connecting the wireless network to an Ethernet backbone, whereas the residential gateway connects it to an ISP (via xDSL/cable modem), and those two kinds of products are usually not fully interchangeable.
 
How can I avoid interference?
If you are using the router and one or more access points in close proximity to one another, and they are set on the same channel, interference will be generated. To avoid interference, be sure to set the router and all access points to different channels (frequencies). In other words, assign a unique channel to the router and each access point.
 
How can I do a site survey?
Use your laptop and the WLAN card and the card's configuration and monitoring utility (or a program like Netstumbler). Make sure the WLAN cards you purchased have a site survey function. All access points/gateways around the air will show up, each identified with its SSID and MAC ID. (If the SSID is identical for multiple APs, use MAC ID to distinguish them.) Choose the AP/gateway you want to associate with, moving the PC to any locations where you want to make communication. Then, record the link quality/signal strength values in the utility and continuously ping the AP/gateway.
 
How can I resolve issues with signal loss?
There is no way to know the exact range of your wireless network without testing. Every obstacle placed between the Router and a wireless PC will create signal loss. Lead glass, metal, concrete floors, water and walls will inhibit the signal and reduce range. Start with the router and your wireless PC in the same room and move it away in small increments to determine the maximum range in your environment.

You may also try using different channels, as this may eliminate interference affecting only one channel.

 
How many channels/frequencies are available with the router?
There are eleven available channels, ranging from 1 to 11 in North America, 1 to 13 in Europe, and varies in other geographic regions.
 
How many ports can be simultaneously forwarded?
Theoretically, the router can establish 520 sessions at the same time.
 
How much will using WEP impact performance?
Using WEP can degrade wireless performance by around 3–10%, particularly for the small UDP packets.
 
How will I be notified of new router firmware upgrades?
All Xwire firmware upgrades are posted on the Xweb site at, where you can download them for free. To upgrade the router's firmware, use the System screen in the Xwire Management utility.
 
I have excellent signal strength, but I cannot see my network. What should I do?
Security such as WEP is probably enabled on the router, but not on your wireless adapter (or vice versa). Verify that the same WEP keys and levels (64 or 128) are being used on all nodes of your wireless network.
 
If DMZ Hosting is used, does the exposed user share the public IP with the router?
No.
 
Since the gateway was set up, FTP cannot pass through it. What should I do?
Disable "Passive" in your FTP client.
 
What affects the wireless LAN throughput?
Physical factors such as range, room layout, thickness of the walls, and radio interference greatly affect wireless throughput. If the PC client and access point are located close together, the access point firmware (driver, bridge) and card driver will dominate the wireless LAN throughput. Solutions to consider:
  • Select products with good sensitivity and higher transmit power
  • Use high-gain antenna or diversity
  • Put access point/gateway in the middle of cell
  • Do not use WEP
 
What causes RF interference and how can I correct it?
Generally, the problem of RF interference is not serious. The WLAN uses spread spectrum technology for anti-interference. The following is a list of appliances that can interfere with a WLAN, and solutions for each situation.
  • Microwave ovens Microwave ovens operating within ten feet or so of an access point or radio-equipped user will generally just cause 802.11b performance to drop. If the performance drop is noticeable, simply move the access point or device so that it is out of that ten foot range.
  • Cordless phones The most damaging of these are 2.4 GHz wireless phones now used in some homes and companies. If one of these phones is in use within the same room as an 802.11b wireless LAN, expect poor wireless LAN performance. In these cases, change the cordless phone channel.
  • Bluetooth enabled devices Bluetooth enabled devices—such as laptops and PDAs—cause performance degradations if operating in close proximity to 802.11 stations, especially if the 802.11 station is relatively far away (i.e., low signal levels) from the station that it's communicating with. The 802.11 and 802.15 standards groups, however, are working on a standard that will enable the coexistence of Bluetooth and 802.11 devices.
  • Other 802.11b devices Other wireless LANs in the neighborhood using the same channel as yours may cause performance degradation. Work with the other users to select different 802.11b channels.
 
What factors cause the poor link quality in a home environment?
Metal objects (RF cannot penetrate metal) - As the RF radio wave can be easily reflected, refracted by the metal objects, change the gateway/AP location or move the antenna so that it's pointing away from any metal.

Walls - 2.4GHz radio should pass through at least one interior wall that does not contain steel.

Neighbor WAN cell using the same channel - Use the station utility to scan if other AP exists. If some overlapped cell is using the same channel, change the channel of AP/gateway.

 
What IEEE 802.11b features does the router support?

The router supports the following IEEE 802.11b functions:

  • CSMA/CA plus acknowledge protocol

  • Multi-channel roaming

  • Automatic rate selection

  • RTS/CTS feature

  • Fragmentation

  • Power management

 
What is 802.11 authentication?
IEEE 802.11 defines two types of authentication: open system and shared key. Open system authentication is a null authentication algorithm. Shared key authentication is an algorithm where both the access point and the client station share an authentication key to perform a checksum on the original message. By default, IEEE 802.11 devices operate in an open system network where any wireless device can associate with an access point without authorization. A wireless device with a valid shared key is allowed to associate with the access point. Authentication management messages (packets) are unicast. This means that authentication messages transmit from one access point to one client only, and are not broadcast nor multicast.
 
What is a site survey?
Once the gateways/APs are installed, IT personnel can test the implementation by roaming the premises with a laptop and observing variations in signal strength. A poor signal or poor throughput at a particular location indicates that an adjustment in Gateways/AP placement, density, or channel selection is necessary to correct the problem in that location.
 
What is DMZ Hosting?
A demilitarized zone (DMZ) allows one IP address (computer) to be exposed to the Internet. Some applications require multiple TCP/IP ports to be open. It is recommended that you set your computer with a static IP if you want to use DMZ hosting.
 
What is ISM band?
The FCC and its counterparts outside of the U.S. have set aside bandwidth for unlicensed use in the ISM (Industrial, Scientific, and Medical) band. The spectrum in the vicinity of 2.4 GHz, and this is being made available worldwide. This presents a truly revolutionary opportunity to place convenient high-speed wireless capabilities in the hands of users around the globe.
 
What is link quality and signal strength?
The signal strength value shows the RSSI received RF signal strength. In brief, it indicates the absolute signal strength. The link quality value shows the receiver SNR (signal noise ratio) or the degree of PN code correlation. It indicates the signal purity relative to noise.
 
What is roaming, and does the gateway support it?
In general terms, roaming is defined as the ability of a PC user to communicate continuously while moving freely throughout an area greater than that covered by a single access point. Before using the roaming function, users need to make sure that their machines use the same channel number as the access point of dedicated coverage area. To achieve true seamless connectivity, the wireless LAN must incorporate a number of different functions. Each node and access point, for example, must always acknowledge receipt of each message. Each node must maintain contact with the wireless network, even when not actually transmitting data. Achieving these functions simultaneously requires a dynamic RF networking technology that links access points and nodes. In such a system, the user's end node undertakes a search for the best possible access to the system. First, it evaluates such factors as signal strength and quality, as well as the message load currently being carried by each access point and the distance of each access point to the wired backbone. Based on that information, the node next selects the right access point and registers its address. Communications between end node and host computer can then be transmitted up and down the backbone.

As the user moves on, the end node's RF transmitter regularly checks the system to determine whether it is in touch with the original access point or whether it should seek a new one. When a node no longer receives acknowledgment from its original access point, it undertakes a new search. Upon finding a new access point, it then re-registers, and the communication process continues.

There are different types or levels of roaming:

  • Seamless roaming across access points with the same SSID but with different channels. The station always resides in the same IP subnet, using the access point with the strongest signal.
  • Roaming across gateways with the same SSID and unchanged IP address. This should work, but with some latency.
  • Roaming across gateways with different IP subnets. This is problematic because the station PC has to be manually released and renewed if the DHCP lease time not expired. However, for client PCs with Windows 2000/XP, the PC can automatically release/renew the IP configuration and be linked to the new gateway, after a short delay.
  • Portable station from office to home, and from home to office. In this situation, the station uses DHCP and the SSID is set to "any."
  • Roaming across IP subnets while not using DHCP. In these cases, try mobile IP.
 
What is Spread Spectrum?
Spread Spectrum technology is a wideband radio frequency technique developed by the military for use in reliable, secure, mission-critical communications systems. It is designed to trade off bandwidth efficiency for reliability, integrity, and security. In other words, more bandwidth is consumed than in the case of narrowband transmission, but the trade-off produces a signal that is, in effect, louder and thus easier to detect, provided that the receiver knows the parameters of the spread-spectrum signal being broadcast.
 
What is the IEEE 802.11b standard?
It is one of the IEEE standards for wireless networks. The 802.11b standard allows wireless networking hardware from different manufacturers to communicate, provided that the hardware complies with the 802.11b standard. The 802.11b standard states a maximum data transfer rate of 11Mbps and an operating frequency of 2.4GHz.
 
What is the performance of WLAN?
If one user is connected to the WLAN, that user gets the full bandwidth. The bandwidth reduces in proportion to the number of users connected at any one time. In general, a maximum of 10–15 users simultaneously connected to one gateway or access point (AP) is recommended. For installation of more than 15-18 laptop PCs, consider adding a second AP so that the load can be distributed evenly.
 
What is the remedy for the RF interference?
One of the best remedies for 802.11b RF interference is to ensure that the wireless LAN has strong signals throughout the areas where users need access. If wireless LAN signals get too weak, interfering signals become more troublesome. Of course, this means that you should do a thorough RF site survey to determine the most effective number and placement of access points or gateways.
 
What is WEP?
WEP is Wired Equivalent Privacy, a data privacy mechanism based on a 64-bit or 128-bit shared key algorithm, as described in the IEEE 802.11 standard.
 
What should I do when I change the SSID and then receive an error?
After you change and save the SSID on your access point/gateway, you need to also change wireless network card' s associated SSID.
 
Where do I need a gateway?
We recommend using a gateway/router/access point in the following situations:
  • In locations where broadband WAN access is required.
  • In the boundary of IP subnets.
  • In locations that require wireless LAN access.
  • In situations where you need firewall protection.
  • In the IP address shortage area (because a gateway provides IP sharing).
  • In situations where you need the server functions (for example, DHCP server and DNS proxy) provided by the gateway.
In summary, we recommend using a gateway in each SOHO, home, workgroup, or department.
 
Which modems are compatible with the router?
The router is compatible with virtually any cable or DSL modem that supports Ethernet.
 
Will 128-bit WEP communicate with 64-bit WEP ?
No. Although 128-bit WEP also uses a 24-bit initialization vector, it uses a 104-bit as secret key. Users need to use the same encryption level in order to make connection.
 

Hardware

What is a MAC Address?
The Media Access Control (MAC) address is a unique number assigned by the manufacturer to any Ethernet networking device, such as a network adapter, that allows the network to identify it at the hardware level. For all practical purposes, this number is usually permanent. Unlike IP addresses, which can change every time a computer logs onto the network, the MAC address of a device stays the same, making it a valuable identifier for the network.
 
What should I know about the WLAN/LAN/WAN/WWAN MAC addresses?
  • The MAC addresses are controlled by IEEE and are globally unique. The MAC ID is unique for each unit.
  • WLAN and LAN share the same MAC ID, and the WAN MAC ID is equal to the LAN MAC ID plus 1 for each gateway unit.
  • The WLAN/LAN MAC ID is shown on the product FCC/MAC label. Because it is programmed at the factory, you cannot change it. Even if you change the wireless card inside the gateway, the WLAN ID is unchanged.
  • You can see the MAC ID of the WAN and LAN in the Interface Settings screen of the Xwire Management utility.
  • In some special cases, you can change the WAN MAC ID in the Xwire Management utility.
 

Installation

Where is the router installed on the network?
In a typical environment, the Router is installed between the cable/DSL modem and the LAN. Plug the router into the cable/DSL modem's Ethernet port.
 

Configure

Does Xwire router support DMZ ?
Yes
 
How are the IP address ranges allocated to the backhaul interfaces?
The backhaul interface is configure using zeroconf. Zeroconf is short for zero configuration IP networking, a method of network devices via an Ethernet cable without requiring configuration and administration. Zeroconf is able to allocate addresses without a DHCP server, translate between domain names and IP addresses without a DNS server, and find services, such as a printer, without a directory service. For additional information see Auto configuration for IP Networking: Enabling Local Communication.
 
How can I check whether I have static or DHCP IP Addresses?
Consult your ISP to obtain this information.
 
How do I get Half-Life:Team Fortress to work with the router?
The default client port for Half-Life is 27005. The computers on your LAN need to have "+clientport 2700x" added to the HL shortcut command line; the x should be 6, 7, 8, and so on. This lets multiple computers connect to the same server.
 
How do I get mIRC to work with the Router?
Set the firewall to forward 113.
 
I am not able to open the Web configuration screen for the Router. What can I do?

You may have to remove the proxy settings on your Internet browser (for example, Netscape Navigator or Internet Explorer). Or remove the dial-up settings on your browser. Check with your browser documentation, and make sure that your browser is set to connect directly and that any dial-up is disabled.

For Internet Explorer, click Tools, Internet Options, and then the Connection tab. Make sure that Internet Explorer is set to Never dial a connection. For Netscape Navigator, click Edit, Preferences, Advanced, and Proxy. Make sure that Netscape Navigator is set to Direct connection to the Internet.

 
What are the firewall default open ports for the WAN interface?

The following TCP and UDP ports are opened to accommodate the basic router application and WAN interface protection. These defaults are implemented in /conf/firewall.system.


TCP Port

Service

22

ssh

80

http

443

https

53

dns

113

auth

520

routing

521

routing


UDP Port

Service

53

dns

113

auth

161

snmp

162

snmptrap

1194

openvpn

5000

openvpn

6277

DCC spam controller



 
What is DHCP server behavior?
The DHCP client will lease an IP address for a period of 'lease time." The server will also "advise" the client that it should use 255.255.255.0 as its subnet mask. For example, the LAN default is set up as 192.168.111.255 as its broadcast address, 192.168.111.1 as the router gateway, and 192.168.111.1 as its DNS servers.
 
What is network address translation and what is it used for?
Network address translation (NAT) translates multiple IP addresses on the private LAN to one public address that is sent out to the Internet. This adds a level of security since the address of a PC connected to the private LAN is never transmitted on the Internet. Furthermore, NAT allows the router to be used with low cost Internet accounts, such as DSL or cable modems, when only one TCP/IP address is provided by the ISP. The user may have many private addresses behind this single address provided by the ISP.
 
What is the maximum number of IP addresses that the router supports?
The defualt configuration supports up to 253 client IP addresses on the LAN and WLAN interfaces.
 
Why do I get a 0.0.0.0 IP address after a DHCP request?
The 0.0.0.0 address is a temporary setting before dhcp client acquires the IP address.
 

Gateway

My ISP gave me a dynamic IP. How can my gateway Web server be accessed from Internet?
We recommend that you to apply a domain name from the ISP that provided the dynamic DNS. Then Internet visitors can access your gateway with the fixed domain name instead of dynamic IP. See the DDNS screen in the Xwire Management utility.
 
What is PPPoE?
Point-to-Point Protocol over Ethernet is a proposal specifying how a host personal computer (PC) interacts with a broadband modem to achieve access to the growing number of high speed data networks. Relying on two widely accepted standards, Ethernet and the point-to-point protocol (PPP), the PPPoE implementation requires virtually no more knowledge on the part of the end user other than that required for standard dial-up Internet access. In addition, PPPoE requires no major changes in the operational model for Internet Service Providers (ISPs) and carriers. The significance of PPP over Ethernet has to do with its far greater ease of use versus competing approaches. By making high speed access easier to use for end consumers, and more seamless to integrate into the existing infrastructure for carriers and ISPs, PPPoE could speed the widespread adoption of high speed access services.

Also, PPP over Ethernet provides a major advantage for service providers by maximizing integration with—and minimizing disruption of—service providers' existing dial network infrastructures. Through tight integration with existing back office automation tools that ISPs have developed for dial-up customers, PPPoE enables rapid service deployment and cost savings. From authentication, accounting and secure access to configuration management, PPPoE supports a broad range of existing applications and services.

The base protocol is defined in RFC 2516.

 
What is the advantage of IP sharing/virtual servers?
The following are examples of applications/servers you can set up when you have one gateway in your home that uses just one dynamically assigned IP address:
  • A family-owned Web site
  • An FTP server
  • A Web camera
  • An IP phone
  • Internet games
 
What is the difference between a gateway and an access point?
n general, a gateway is more powerful and includes an access point function in addition to a WAN interface, routing, NAT masquerade, DHCP, DNS, and other applications.
 
What should I do if I cannot communicate with the router through a WAN connection?

Try the following:

  • Verify network configuration by ensuring that there are no duplicate IP addresses. Power down the device in question and ping the assigned IP address of the device. Ensure that no other device responds to that address.

  • Check that the cables used have proper pin outs and connectors, or use another LAN cable.

  • Check that the hub, switch, or computer to which the router connected, and make sure all devices support 10/100Mbps speed.

This is what you will see if the router is properly connected to the WAN port and LAN port 3 on the switch port at 100Mbps:



You won't be able to tell if the connection is bad by looking at only the Link LED. You also need to look at the Hub LED if you are not sure what kind of hub the router is attached to.

 
Why is it called gateway server?
The gateway server is so named because it supports several server functions: IP masquerade server (IPTABLES), Port mapping (IPTABLES), DHCP server, and Web server.
 
Why would Dynamic DNS be used?
Typically, computers on the Internet are located using a numbering scheme called IP addressing. However, IP addresses such as 192.168.76.229 can be difficult for people to remember, so a scheme called DNS (Domain Name Service) was developed. DNS is a database that maps a human-friendly name, a domain name, to an underlying IP address. For instance, DNS allows you to type www.yahoo.com instead of 64.58.76.229 to get to Yahoo!.

Not only are IP addresses difficult to remember, but they may not even stay the same. Most Internet service providers assign dynamic and not static IP addresses to their subscribers. A dynamic IP address means that every time you connect to your ISP or at certain intervals, your computer's IP address may change. This poses a problem if you try to run a server using a dynamic IP address, since the domain name-IP address mapping in DNS will become invalid at every change. Visitors might be sent to a different or invalid machine if they try to use a domain name to get to your computer.

A Dynamic DNS service solves these issues by allowing you to use an easy to remember domain name instead of an IP address to help others locate your computer. It also constantly monitors any changes in your machine's IP address and updates the domain name-IP address mapping in DNS.

 
Why would PPPoE be used?
PPPoE is used to allow Internet Service Providers (ISPs) the use of their existing RADIUS authentication systems from their dial-up service on a broadband/Ethernet based service. It also allows for ISPs to resell the same line multiple times.
 

Security

Are any security mechanisms used in wireless LANs?
There are several security mechanisms used in wireless LANs:
  • Normal use. Wireless LAN access is restricted to small area, because of the limited range of radio. Most "attacks" are along the lines of your neighbor accidentally connecting to your network due to improper configuration. Directional antennas will allow the attacker to be further away than regular nodes, but only with line of sight. But this limits greatly the scope of the risk. Logistics. Because wireless LANs use digital transmissions, a would-be attacker cannot listen in with a regular radio scanner. The only practical way to attack a wireless LAN is to use another wireless card that is compatible with the LAN. An attacker who breaks in this way is likely to try to do two things: eavesdrop on your communications (for example, read an e-mail message you are sending) or access your resources (for example, your Internet connection).
  • Network identifiers. For most users, the network identifier (i.e., the SSID) is enough protection against casual users: other people can't accidentally join your network, unless they guess the correct network identifier or purposely try to attack you. AP broadcast beacons can expose SSIDs, but if you have an AP the like Xwire router, you can can disable SSID broadcast. When you disable SSID broadcast, intruders cannot find out the SSID using their card's utility.
  • 40- or 128-bit RC4 Wired Equivalent Privacy (WEP) authentication. WEP provides two levels of security: authentication and encryption. Although WEP is still considered weak by some experts because of the distributed single key and the lack of per-packet authentication, it is better than nothing. With these schemes, each packet transmitted over the network is individually encrypted, and the card refuses unencrypted data. This encryption is totally transparent to the higher layer and the user only needs to set the same encryption key in the APs/gateways and all nodes of the network.
  • MAC-level access control. Most gateways check the WLAN station's MAC ID with the user-configured access table, to allow or deny some the station's pass through to the LAN port (intranet) or WAN port (Internet). Access control. You can control who has access by requiring user names and passwords, and by configuring when and for how long users can have access.
  • VPN (IPSec, PPTP). This security solution is independent of the wireless link. You will need to set up a VPN gateway on the other side of the APs and the VPN software on every wireless device. For example, a link is something like:
  • WLAN station–AP–VPN gateway The above is usually complicated to set up, but that's the price for security. PPTP client is provided in Windows, and PPTP server is implemented in the gateway. A private tunnel is built between the client and server.
  • 802.1x. This future solution is based on the upcoming 802.1X security standard, which enables port-level access control. Microsoft will promote this in handheld devices (using Windows XP). A standard set of instructions is expected to strengthen WEP. IEEE 802.11i. This standard provides a much stronger way of encrypting data passed over the network. Safeguards you can take. There are simple things you can do to protect your gateway from intruder access. Place the gateway in a secret place, and position it so that the hardware's Reset button is not easy to see. Also, put authentication checking is place for the gateway's GUI access so that only certain user names (with passwords) can open the GUI and make modifications.
  • Proprietary solutions.
 
Can I configure my Xwire router as a VPN gateway?
Yes
 
Does the router pass PPTP packets or actively route PPTP sessions?
The router allows PPTP packets to pass through?
 
Does the router support IPSec passthrough?
Yes, it is a built-in feature that the router automatically enables.
 
How can I find out if any intruders entered my router?
Uhhh?
 
How can I prevent intruders from accessing my router with SSID=any?
  • Enable and set WEP keys, and only give the key to authorized clients. Frequently change the WEP key.
  • Enable and set access control by MAC address.
 
How can I secure my network?

It is very important to follow the vendor's recommendations for securing your wireless devices and systems. If you no longer have the documentation, you can probably obtain it from the vendor's Web site.

To secure your wireless network, think C, D, E, F (Change, Disable, Encrypt, Filter/Firewall).

General recommendations for securing your network are as follows:

  • Change the username and password for your router from the default.
    Make passwords long and difficult to guess.

  • Change the SSID from the default and disable SSID broadcasting.
    Make the SSID long and difficult to guess. Also block any non-essential network services and broadcast messages.

  • Enable WEP security.
    Generate or supply a key, and populate the clients with the key.
    Make encryption keys long and difficult to guess, and frequently change them.

  • Configure the MAC address filter list and restrict access to those addresses.
    The only MAC addresses you should allow are the ones on your internal network.

  • Periodically upgrade the firmware and software on wireless devices and PCs.
    You should also do this with your personal firewalls and anti-virus software.

Note: These recommendations are security "best practices" that should fit most situations. This list is not intended to be comprehensive, and you may need to make adjustments for your situation.

 
How does your RADIUS solution handle (delegate) bandwidth assignment to individual users?
Bandwidth delegation to individual users authenticating on the wireless network is ...
 
Is the node-to-node traffic encrypted?
Yes it can using WEP, WPA-PSK, or SSL tunnels.
 
What are some general suggestions for protecting user and server data from hackers?
  • Don't put the servers in the WLAN.
  • Disable other unwanted protocols (for example, IPX and NetBIOS) to increase overall network performance.
  • Don't open shared folders or files on the WLAN.
  • Use a WEP key.
 
What are the differences between 40-, 64-, and 128-bit WEP keys?
64-bit WEP is the same as 40-bit WEP. The lower level of WEP encryption uses a 40-bit (10 hex character) "secret key" (set by the user), and a 24-bit "initialization vector" (not under user control). Some vendors refer to this level of WEP as 40-bit, others as 64-bit. Either way, they're the same encryption level and can interoperate. The higher level of WEP encryption, commonly referred to as 128-bit WEP, actually uses a 104-bit (26 hex character) "secret key" (set by the user), and a 24-bit "initialization vector" (not under user control).
 
What is a RADIUS Server?
RADIUS (Remote Authentication Dial-In User Service) is used for centralizing network authentication of remote access users. When you connect to an ISP you must enter your user name and password. This information is passed to a RADIUS server, which checks that the information is correct, and then authorizes access to the ISP system. RADIUS includes three components: an authentication server, client protocols, and an accounting server. The RADIUS authentication server is installed on a central computer on the network. The client protocols run on remote access devices such as remote access routers and firewalls. These RADIUS clients send UDP authentication requests, typically over port 1812, with MD5 encrypted passwords to the RADIUS authentication server and act on responses sent back by the server. RADIUS accounting captures statistics about sessions that are established to the network, and typically operates over UDP port 1813.
 
What security mechanisms are provided?
  • Wireless 40/128-bit WEP authentication and encryption
  • Basic firewall
  • Access control by MAC address
  • VPN
 
Will the information be intercepted while it is being transmitted through the air?
WLAN features two-fold protection in security. On the hardware side, as with Direct Sequence Spread Spectrum technology, it has the inherent security feature of scrambling. On the software side, WLAN offers the encryption function (WEP) to enhance security and access control.

 

Compatibility

Can I run an application from a remote computer over the wireless network?
This depends on whether the application was designed to be used over a network.
 
Does the router support ICQ send file?
Yes, with the following fix. In your ICQ program, click ICQ menu -> preference -> connections tab->, and check I am behind a firewall or proxy. Then set the firewall timeout to 80 seconds in the firewall setting. The Internet user can then send a file to a user behind the router.
 
Does the router support IPX or AppleTalk?
No. TCP/IP is the only protocol standard for the Internet and has become the global standard for communications. IPX, a NetWare communications protocol used only to route messages from one node to another, and AppleTalk, a communications protocol used on Apple and Macintosh networks, can be used for LAN to LAN connections, but those protocols cannot connect from the Internet to a LAN.
 
I set up an Unreal Tournament Server, but others on the LAN cannot join. What do I need to do?
If you have a dedicated Unreal Tournament server running, you need to create a static IP for each of the LAN computers and forward ports 7777, 7778, 7779, 7780, 7781, and 27900 to the IP address of the server. You can also use a port forwarding range of 7777 – 27900. If you want to use the UT Server Admin, forward another port. Then in the section of the Server.ini file, set the ListenPort to 8080 (to match the mapped port above) and ServerName to the IP assigned to the router from your ISP.
 
Is the router cross-platform compatible?
Any platform that supports Ethernet and TCP/IP is compatible with the router.
 
What operating systems does the router support?
The router supports clients using most operating systems such as Windows, Linux, and MAC.
 
What Web browsers can I use with the Xwire Management utility?
You can use Internet Explorer 5.0 or later, Netscape 7.0 or later, Opera 7.5 or later, Firefox 1.0 or later, and some PDA browsers for example, Opera).
 

Access Pointi

How can I prevent intruders from accessing my Xwire router with SSID=any?
Disable the SSID broadcast to prevent clients from using SSID=any to access the wireless LAN.
 
Is it possible to connect the router directly to a cable, ISDN, or xDSL line?
Yes, you can connect the Xwire router to a cable, ISDN, or xDSL modem with a crossover cable. For some xDSL, you may have to change the firewall configuration so that it can work with the PPPoE protocol.
 
What is ad-hoc mode?
When a wireless network is set to ad-hoc mode, the wireless-equipped computers are configured to communicate directly with each other.

The 802.11 standard supports two network topologies: ad–hoc and infrastructure mode. A standalone ad–hoc network topology consists of at least two wireless stations without using access points.

This is often referred to as a peer-to-peer network because it can be constructed quickly without much planning overhead. Ad–hoc mode LANs are normally less expensive because they do not require a dedicated computer to store applications and data. However, they do not perform well for large networks.

Figure 5-2: Infrastructure mode

 
What is infrastructure mode?

When a wireless network is set to infrastructure mode (also known as master mode), the wireless network is configured to communicate with a wired network through a wireless access point. This mode is also referred to as “master” or “access point” mode.

Figure 5-2: Infrastructure mode.

 
What is managed mode?

When a wireless network is set to managed mode, the device can connect to devices set to master or infrastructure mode.

Figure 5-3: Managed mode.


What is FHSS? What is DSSS? And how do they differ? Frequency-Hopping Spread Spectrum (FHSS) uses a narrowband carrier that changes frequency in a pattern that is known to both transmitter and receiver. Properly synchronized, the net effect is to maintain a single logical channel. To an unintended receiver, FHSS appears to be short-duration impulse noise.

Direct-Sequence Spread Spectrum (DSSS) generates a redundant bit pattern for each bit to be transmitted. This bit pattern is called a chip (or chipping code). The longer the chip, the greater the probability that the original data can be recovered. Even if one or more bits in the chip are damaged during transmission, statistical techniques embedded in the radio can recover the original data without the need for retransmission. To an unintended receiver, DSSS appears as low power wideband noise and is rejected (ignored) by most narrowband receivers.

 

Routing

What is the routing protocol for the mesh network?
The default is OLSR. It is also possible to use AODV or OSPF.
 
What size of deployment (in terms of number of nodes) does the OLSR implementation handle in one network?
Theoretically, a lot of units can join the mesh network, but the performance is predicated on number of hops to the default routes and the number of links at the hub neighbor nodes.