ABSOLUTELY a difference. UDP is a very low overhead protocol. Its basically send the packet and pray it gets there. (No pun intended). There is no ACK on UDP.. DNS uses UDP (so does ping). If receiver doesn't get dat.. it takes a time-out timer at a higher OSI layer (application layer) to tell it to resend because it did not get the response it expected from the receiver (i.e. in the case of DNS.. didn't get response...). Where in TCP, you actually have an ack from the receiver at this layer.
Its like comparing Frame Relay to Ethernet... -----Original Message----- From: "Jason" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Date: Tue, 24 Jun 2003 17:29:24 -0400 Subject: RE: [smartBridges] speed > Speaking of this, is there any difference with UDP as opposed to TCP? I > have noticed 6Mbps+ with camera data alongside other web/email traffic, > and I think the camera is streaming using UDP... > > Jason > > > Sorry, cannot agree with that statement. Just because a system uses > > half-duplex does not mean that the speed is halved. It will only be > > halved if the acknowledgement packets are of the same length as the > > transmission packets and this is very rarely the case. For example, > > if you send blocks of 10k and the acknowledgement packet is only 0.1k > > then the time spent transmitting will be about 100 times longer than > > the time spent receiving (even considering the time spent switching > > between transmit and receive and the overhead in synchronizing. > > > > We did a lot of tests on this matter to try and determine some rule > of > > > thumb that we could use. We had heard that 60% would be a suitable > > value to use, but in our tests we never got above 40% i.e 4Mbps for > > 802.11b but and 20Mbps for 802.11g > > > > The above tests were all carried out in a single room with no other > > 2.4GHz equipment turned on within miles (tests were done on islands). > > We were getting nearly 100% in terms of signal strength and link > > quality. However, there was the possibility of reflections from the > > walls of the room causing problems which we had no way of > > investigating. Last week-end we miraculously got in excess of 40Mbps > > in an outdoor environment using 'g' equipment over a distance of > about > > > 100 meters. This was noted as an 'accidental' sidebar to a bigger > test > > > and we have not yet had a chance to re-check the figures. > > > > Hope my ramblings are of some help and did not sow seeds of > confusion. > > > > Oliver Leamy > > > > Ogenek Teoranta, Ballingeary, Macroom County Cork > > +353 (26) 47808 ; +353 (86) 8337664 > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Company 2210 > > Sent: 23 June 2003 21:56 > > To: [EMAIL PROTECTED] > > Subject: Re: [smartBridges] speed > > > > Yep. Wireless is half duplex, so whatever your getting divide by 2 to > > get realistic full duplex throughput. > > > > ----- Original Message ----- > > From: "Roger Howard" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Monday, June 23, 2003 9:49 PM > > Subject: [smartBridges] speed > > > > > > > Is there any way to tell what speed an airBridge is connected at > > without > > > doing a speed test? If it's connected at 1Mbps am I right in > > > assuming > > that > > > the actual throughput will be about half that? > > > > > > Thanks, > > > Roger > > > > > > The PART-15.ORG smartBridges Discussion List > > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> > > > To Remove: mailto:[EMAIL PROTECTED] (in the body type > unsubscribe > > smartBridges) > > > Archives: http://198.63.203.6 > > > > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] > (in > > > the body type unsubscribe > > smartBridges) > > Archives: http://198.63.203.6 > > > > The PART-15.ORG smartBridges Discussion List > > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > > smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] > (in > > > the body type unsubscribe > > smartBridges) > > Archives: http://198.63.203.6 > > > > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in > the body type unsubscribe smartBridges) > Archives: http://198.63.203.6 > > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > smartBridges <yournickname> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > smartBridges) > Archives: http://198.63.203.6 The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://198.63.203.6
