does a wireless router route packets

[rookie1010]

Hello,

If you have a network of say two laptops and a router, with the laptops having an IP address of
laptop 1 192.168.0.1
laptop 2 192.168.0.2

and the router having an IP address of
192.168.0.3

the two laptops and the router are wifi enabled.

now if laptop 1 wants to communicate with laptop 2, then would it communicate through the router. or once the ip addresses have been assigned by the router through DHCP, all communication need not take place through the router.
i mean if the ip packet has the header 192.168.0.2(packet meant for laptop 2), laptop 2 would receive that anyway, does the router need to lay a role in "routing" the packet?

 

[spidey07]

It definately doesn't "route" the packet. Routing works with layer3 addresses (IP).

Now the access point in the router does play a role. An access point is nothing more than a bridge and it bridges (switches, same thing) with layer2 addresses (MAC).

So the frame, including the layer2 header and layer 3 header arrives on the access point, the access point realizes this layer2 address is another wireless client and it simply sends it over the air - making the appropriate encryptions changes of course.

If you think of the wireless as a star topology with the access point in the middle it makes more sense.

 

[rookie1010]

thanks for the reply,

so the topology is still a star with the router/bride in the center. why cant laptop 1 just address the packet to laptop 2, and take the router/bridge out of the scenario.

I mean the packet header with l2 informatio ncan be read by laptop 2's wireless adaptop too, correct?

 

[spidey07]

Because wireless doesn't work that way. All communication is from clients to the access point.

Also unless you are using very simple security there is no way for the clients to decrypt each other's traffic (different keys/certificates). This was done by design to prevent what you are describing.

 

[JackMDS]

When you have a Wireless Router, the Wireless aspect of the connection (Access Point) is set to Infrastructure Mode.

Under this mode, Wireless client can talk to a Wireless Access Point (A Wireless Hub form the Network perspective).

Wireless Client (Wireless computer) cannot talk directly to another Wireless Client.

Wireless Access Point can only talk to a Wireless Client and not to another Access Point.

If Wireless client computers are set to Ad-Hoc mode they can talk one to the other directly (both have to be in Ad-Hoc mode).

Wireless client computers cannot talk to an Access Point when in Ad-Hoc mode.

Wireless Access Point configured as a Bridge can talk one to the other, and cannot talk to clients while in Bridge mode.

Wireless Access Point that can be configured as WDS can talk to both Access Points and Wireless Client.

 

[rookie1010]

thanks for the replies spidey, JackMDS,

it now makes sense, how does one wireless access point talk to another wireless access point?

can more than two computers talk to each other in ad-hoc mode?

and the wireless access point can be configured in three different modes
Infrastruture mode
bridge mode
WDS (wireless distribution mode)

correct?

why three different modes for the wireless access point, why not just the WDS< since it fits all the scenarios?
where would the bridge mode be used?

 

[DainBrammage]

Yes more than two ADHOC all device in tange can share the connection best for very small groups that are in clo0se proximity.

WDS halves your available bandwidth (with single radio APs)

Infrastructure mode = obvious no explanantion needed

Bridge mode connects to physical networks Wirelessly

WDS eliminates the physical media required to connect an access point the air is the media

 

[rookie1010]

thanks for the replies dainbrammage

, i guess the advantage of more than two adhoc devices sharing the connection in ad-hoc mode is the absence of a router, bit rate wise there is no difference.

why does wireless distribution mode half your bandwidth, is it because half the bandwidth is allocated to talking to clients and the other half is allocated for talking to other routers?

if you have two routers in bridge mode, then what are the clients they are servicing?

 

[JackMDS]

Ad-Hoc cannot be used seriously for any thing. If you have some kind of special emergence situation use it, but as a topology solution, it is a ?Dud?. You are dealing with a unit that depends on software driver and the computer?s OS and hardware, and thus work much less efficiently than an Access Point. A Wireless Router is a small hardware computer and can take the main load of the Wireless processing independent from the computer).

WDS cuts half of the Bandwidth because it needs to receive, and then transmit the same information further.

Since Wireless devices below $1000 have only one Radio (one radio can either receive or transmit but can not do both at the same time since the same RF circuit are used for T & R ), they work like walky talky. I.e. Flip-flop between receive and transmit, thus loosing half of the Bandwidth pass the WDS unit.

Two Routers in Pure Bridge Mode connect only one to the other. Let say you have two Buildings each one with its own server and system but you want to connect them into WAN. You are not going to put an available switch in the patio between the buildings for people plugging their computer into an Inter WAN main connector. Same with Wireless Bridge connector.

Do not confuse AP Bridge Mode with what is called Consumers Bridge (Like a Game Box Adaptor) which are regular Client Wireless card that have the Drivers embedded in them so they can be put on a None computer device that does not have the means to load software drivers.

Why both called Bridge? Because in the 21st century consumers market it is Marketing that dominates the information channel Not technology.

Wireless Network - Configuration Modes. ).

Wirelessly Bridging Home / Network.