To point one, it depends on the device and the settings. If set to full duplex, there should not be collisions in a ptp configuration, but some inexpensive equipment will still show collisions. In half duplex, there may be, since only one side can talk at a time. I agree, this is only for CDMA networks.
Tom's discussion in his earlier post is excellent. Tom DeReggi wrote: > For Ethernet colision detection type networks, you are correct. > That is what many WISPs forget when deploying PtMP. They incorrectly think a > CDMA 25mb link will double their 10mb TDD link as they scale. They learn > that as customer get added, the capacity is not nearly as much as they > thought.. > > But with Ethernet backbones it does not always work the same, for two > reasons.... > > 1) There is only one end device, so its not possible for collisions, and > collision avoidance algorythms aren't really needed. > 2) If using TDD Ethernet, transmits are scheduled, without the typical > overhead of Ethernet. > > I can run successfully run a bandwidth test of 95mb over a 100mb Cogent > fiber circuti, and with a Tlink-45 set 36mbps mod, tested to pass 30mbps > with radio tests, I can count on passing 30mbps through it. > So again, it comes down to the design and technology of the backbone. > > Tom DeReggi > RapidDSL & Wireless, Inc > IntAirNet- Fixed Wireless Broadband > > > ----- Original Message ----- > From: "Scott Reed" <[email protected]> > To: "WISPA General List" <[email protected]> > Sent: Thursday, May 20, 2010 11:08 AM > Subject: Re: [WISPA] Bandwidth > > > >> Old rule of thumb for Ethernet, because it is based on collision >> detection, is 70-75% is the max you want. Above this and collisions >> often become an issue. I assume the same is true for the faster links >> as well. >> >> Jeremie Chism wrote: >> >>> At what percentage of your backbone usage do you look at adding more >>> capacity. At peak times I run at 65-70 percent of capacity. Just >>> looking for suggestions. >>> >>> Sent from my iPhone >>> >>> >>> -------------------------------------------------------------------------------- >>> WISPA Wants You! Join today! >>> http://signup.wispa.org/ >>> -------------------------------------------------------------------------------- >>> >>> WISPA Wireless List: [email protected] >>> >>> Subscribe/Unsubscribe: >>> http://lists.wispa.org/mailman/listinfo/wireless >>> >>> Archives: http://lists.wispa.org/pipermail/wireless/ >>> >>> >>> >>> >> -- >> Scott Reed >> Sr. Systems Engineer >> GAB Midwest >> 1-800-363-1544 x2241 >> 1-260-827-2241 >> Cell: 260-273-7239 >> >> >> >> -------------------------------------------------------------------------------- >> WISPA Wants You! Join today! >> http://signup.wispa.org/ >> -------------------------------------------------------------------------------- >> >> WISPA Wireless List: [email protected] >> >> Subscribe/Unsubscribe: >> http://lists.wispa.org/mailman/listinfo/wireless >> >> Archives: http://lists.wispa.org/pipermail/wireless/ >> > > > > -------------------------------------------------------------------------------- > WISPA Wants You! Join today! > http://signup.wispa.org/ > -------------------------------------------------------------------------------- > > WISPA Wireless List: [email protected] > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ > > > -- Scott Reed Sr. Systems Engineer GAB Midwest 1-800-363-1544 x2241 1-260-827-2241 Cell: 260-273-7239 -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
