From owner-freebsd-mobile Sat Aug 17 11:39:58 2002 Delivered-To: freebsd-mobile@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3C0EB37B48A for ; Sat, 17 Aug 2002 11:39:50 -0700 (PDT) Received: from mta5.snfc21.pbi.net (mta5.snfc21.pbi.net [206.13.28.241]) by mx1.FreeBSD.org (Postfix) with ESMTP id B118843E6E for ; Sat, 17 Aug 2002 11:39:49 -0700 (PDT) (envelope-from fscked@pacbell.net) Received: from pacbell.net ([64.171.191.167]) by mta5.snfc21.pbi.net (iPlanet Messaging Server 5.1 (built May 7 2001)) with ESMTP id <0H10000L83UDFY@mta5.snfc21.pbi.net> for mobile@freebsd.org; Sat, 17 Aug 2002 11:39:49 -0700 (PDT) Date: Sat, 17 Aug 2002 11:42:08 -0700 From: richard childers Subject: Re: IBSS and BSS with multiple FreeBSD Wireless Gateways To: Evren Yurtesen Cc: mobile@freebsd.org Message-id: <3D5E98FF.82CD061E@pacbell.net> MIME-version: 1.0 X-Mailer: Mozilla 4.79 [en] (WinNT; U) Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT X-Accept-Language: en References: Sender: owner-freebsd-mobile@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org I've wondered about this as well. Imagine the following simple scenario. You are WiFi- and FreeBSD-enabled; so is your friend. For the sake of simplicity let's assume that you are directly across from one another in two dormitories at approximately the same height. You both eliminate signal strength and signal security issues with line-of-sight antenna pointed directly into one another's cone of transmission. At this point you are not unlike two routers with a cable between them, and it is only a matter of picking an appropriate class 'C' subnet (IE, 192.something), assigning it an appropriately long mask (IE, one preserving only two bits of the address for actual networking), bringing the interfaces up and adding routing entries on each end. Note that your network is still hypothetically subject to eavesdropping and jamming from parties in either antenna's line of sight. A slightly more complicated scenario emerges when you attempt to add a third node; at this point one of the nodes needs to have two cards, with two addresses and two antennas and two routing entries. I imagine there are some issues with crosstalk between the antennas that would need to be addressed with physical separation and maybe some appropriate shielding; tin foil works, I expect. -- richard Evren Yurtesen wrote: > Is it possible to use FreeBSD with IBSS or BSS mode as a bridge to > overcome line of sight issues? and provide roaming for mobile users? > > What is the biggest problem if we are using IBSS mode? > > Another question is if we are using IBSS mode and 2 clients are close > to each other but the gateway is little bit more far away. Does it cause > the clients to choose each other instead of the gateway because they > have stronger signal? If this happens, wouldnt this cause the link to > the gateway be broken? > > Evren > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-mobile" in the body of the message -- Richard A Childers/KG6HAC -- Senor UNIX System & Network Administrator "Dont forget nothing." Maj Rogers, standing orders, 1st Ranger Bn, 1759 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-mobile" in the body of the message