Remember latency is just as much a layer3 issue NOT only layer2 issue, so its impossible for LAyer2 devices to cure latency.
I don't want to turn this into a thread about whether Trango polling or Canopy polling is better or more consistent. I'll just say that we did our conclusive testing year back, and made our decission. So I'll stick to "polling/oversubscription/latency" in general. The first thing to define is whether all customers have their own dedicated CPE direct to the AP. The second that is not the case, it all changes. We use PtMP to feed remote areas that then have repeaters to serve additionl groups of homes. Or we have 1 CPE serve a tenant building of customers. When this occurs the badnwdith management has to consistently occur at the front end or back end, it can't really solve the problem occurring in the middle at the AP. And sometimes there can be timing issue, if PTMP units are nested several levels deep, when using polling within the APs. These things need to be considered, if having a universal SLA policy for all customers. The other big factor is ARQ. (ps. dont say Canopies don't need arq because their C/I allows them to not have interference :-) The benefits of ARQ are well proven and justifed, which is why Canopy and Trango supports it. If there are ARQ retransmissions, latency WILL rise. You won;t see it from the AP side because the Pings go our right away, but from the client, The ARQ needs to wait for its next time slice to retransmit. Again, I don't want to get into which manufacturer's ARQ is a better implementation. Just pointing out that ARQ is one of hte factors that prevents an ISP from knowing exactly what the latency is that the customer is experiencing, without testing from the customer side. There is no way around it, if an ISP over subscribes, they will get periods of higher latency at some point. I personally believe that most ISPs think their networks perform better than they really do. Polling drastically reduces the latency and makes it way more consistent, but it does not completely solve it, as traffic patterns change. In order for polling to truely solve latency, it would have to dedicate a tiem slot, and USE the capacity even if there was no data to send, which would NOT be efficient, and would overly restrict throughput for custoemrs. Instead "smart" polling mechanisms get deployed, so spectral time is not wasted unused, if a sub could use it. TCP does not like hard inconsistent bandwidth cut offs. That is exactly what occurs when a Sub needs to wait its next scheduled turn to transmits, which turn may not occur at the exact same increment that TCP expects it to. Tom DeReggi RapidDSL & Wireless, Inc IntAirNet- Fixed Wireless Broadband ----- Original Message ----- From: "Anthony Will" <[EMAIL PROTECTED]> To: "WISPA General List" <[email protected]> Sent: Tuesday, November 04, 2008 11:14 AM Subject: Re: [WISPA] heavy usage customers > With Canopy, and a correctly configured polling AP there is no > competition for time slices unless the AP is overloaded. This is how > the latency is consistent. Canopy has what is called control slots. > This is a predetermined time that the SM is allowed to ask for > resources. Increasing control slots can decrease overall bandwidth > available by using up an additional time slice but allows for the > latency to be consistent no matter the load. Basically the latency is > built into the polling system. That is why a Trango, wifi and other > solutions have a starting latency of 4ms vs Canopy at 8ms. The issues > is the busier the Trango, wifi etc. get the higher the latency gets as > the SM / CPE are asking for the AP's attention over top each other. > > Anthony Will > Broadband Corp. > > Tom DeReggi wrote: >> Guaranteeing latency.... >> >> One of the things we learned is that the ISP can't measure the customer's >> experience of latency accurately. And if the can;t measure it, they cant >> guarantee it. >> When pings initiate from the AP side, they always send without delay. >> When pings initiate from the SU side, they can be delayed from the >> polling >> or competing for their timeslice to transmit. >> >> >> Tom DeReggi >> RapidDSL & Wireless, Inc >> IntAirNet- Fixed Wireless Broadband >> >> >> ----- Original Message ----- >> From: "Travis Johnson" <[EMAIL PROTECTED]> >> To: "WISPA General List" <[email protected]> >> Sent: Sunday, November 02, 2008 11:39 PM >> Subject: Re: [WISPA] heavy usage customers >> >> >> >>> Hi, >>> >>> We don't use DHCP. Every single customer gets a real, static IP address. >>> We also a assign a static IP address to every radio (for management). >>> >>> When I posted the question a month ago about how to force an SM to >>> connect to a specific AP on a tower, the only answer was "color code". >>> This isn't really an option, as that means the installer has to change >>> the color code in the field. All of our current radios are setup and >>> ready to connect to ANY tower and ANY AP on that tower without the >>> installer doing anything in the field. >>> >>> And how does first level tech support even find the correct radio in the >>> AP list for a customer on the phone? They have to scroll through 160 >>> people to find them by MAC address? >>> >>> Yes, Canopy is a slower radio in today's world. 14Mbps of total >>> throughput on a 20mhz channel is SLOW. Using Mikrotik I can get 30Mbps >>> (double the speed) on the same channel size. Or I can use a 10mhz >>> channel and get 15Mbps. And all these speeds can be delivered via upload >>> or download or any combination, I don't have to set a specific >>> percentage of up/down. >>> >>> And how do you guarantee 7ms latency? What happens if a customer gets >>> 8ms? And how do they test that measurement? And what happens when a >>> customer completely clobbers an AP and 160 customers are getting 20ms >>> latency? Or you have interference from a new provider and all those >>> people get 100ms latency? >>> >>> Travis >>> Microserv >>> >>> >>> Chuck McCown - 3 wrote: >>> >>>> All of the complaints are easily overcome with the proper management >>>> software, DHCP reservations etc. You can easily force the SM to >>>> connect >>>> to the exact AP you want a couple different ways. And there are >>>> several >>>> non motorola software packages that do this kind of stuff. We have >>>> 5000 >>>> subs on it and we don't break a sweat in managing any of this. >>>> >>>> We put 128-160 customers per AP and they all still get 10.2 Mbps burst. >>>> Slower radio? That seems pretty fast to me. >>>> And we guarantee latency to 7 mS. Hmmm, that is pretty hard to do with >>>> anyone else. >>>> ----- Original Message ----- >>>> From: Travis Johnson >>>> To: WISPA General List >>>> Sent: Sunday, November 02, 2008 1:39 PM >>>> Subject: Re: [WISPA] heavy usage customers >>>> >>>> >>>> We've tried Canopy... twice in fact... once about 3 years ago, and >>>> once >>>> about a month ago. We just can't make it fit into our network >>>> management >>>> (IP database, Call tracking, customer management, etc.) system very >>>> well... having customer radios that change their LUID and IP address >>>> every time they register, having to set the bandwidth on each SM >>>> instead >>>> of the AP, having no security or ways to control which AP a customer >>>> connects to without having to buy their software, etc. >>>> >>>> All that, plus paying MORE for a slower radio than what we are using >>>> just didn't make sense. I can put up an AP (2.4ghz, 5.3ghz, 5.4ghz, or >>>> 5.8ghz) for less than >>>> $400 that will support 50 customers, using only 10mhz wide >>>> channels... >>>> and each CPE is less than $175 complete (including PoE, antenna). >>>> >>>> Canopy seems to work well for many people... but I've never been one >>>> to >>>> follow the "norm". And I get to put $50 in my pocket on every install, >>>> and $1,000 for every AP we put up. ;) >>>> >>>> Travis >>>> Microserv >>>> >>>> Chuck McCown - 3 wrote: >>>> Well that is a testimony to your quality of service for sure. >>>> Now, if you were using Canopy your customers would be even happier! >>>> >>>> ----- Original Message ----- >>>> From: "Travis Johnson" <[EMAIL PROTECTED]> >>>> To: "WISPA General List" <[email protected]> >>>> Sent: Sunday, November 02, 2008 11:07 AM >>>> Subject: Re: [WISPA] heavy usage customers >>>> >>>> >>>> I have Qwest DSL, CableOne, another WISP (doing "up to 4meg" for >>>> $29.95 >>>> with Canopy), and a licensed WiMax (2.5ghz) provider (doing "up to >>>> 2meg", mobile, for $29.95). I have a lot of competition... and yet we >>>> have no sales people, no real advertising campaign, and more installs >>>> than we can keep up with each month. >>>> >>>> Travis >>>> Microserv >>>> >>>> Chuck McCown - 3 wrote: >>>> You must not have competitors. I have both Qwest and Comcast >>>> giving >>>> away >>>> multi megabit starting at $15.95 >>>> ----- Original Message ----- >>>> From: Travis Johnson >>>> To: WISPA General List >>>> Sent: Sunday, November 02, 2008 10:53 AM >>>> Subject: Re: [WISPA] heavy usage customers >>>> >>>> >>>> I guess that's my point... why offer more bandwidth than you have to? >>>> Most people don't need more than 1meg, and that's our most popular >>>> package for $39.95 per month (total, no modem rental fee, etc.). Why >>>> give >>>> away the farm if you don't have to? :) >>>> >>>> Travis >>>> Microserv >>>> >>>> RickG wrote: >>>> Wow, with all that bandwidth, I'm surprised you dont offer higher >>>> speeds. >>>> >>>> Technically speaking, the download & upload price is the same. From a >>>> cost standpoint, I allocate the download & upload separately because I >>>> am "forced" to pay dearly ($1200/month) to AT&T for my dual T1's which >>>> are required for "decent" upload speeds. Right now, my traffic is >>>> split so all port 80 traffic flows though the 4Mbps x 2Mbps connection >>>> through Time Warner which runs over $500/month. This works fairly well >>>> for now since about half the traffic is web browsing. When I bought >>>> this WISP there was no management, monitoring or reporting. I took >>>> care of the management & monitoring and I'm working on the reporting. >>>> The best thing I've done is replace the StarOS firewall with Mikrotik >>>> and set up traffic priority. >>>> Whew! Lots of work. At any rate, I'm working on my upstream connection >>>> next. I really need to get the cost down. >>>> >>>> Thanks! -RickG >>>> >>>> On Sun, Nov 2, 2008 at 12:08 PM, Travis Johnson <[EMAIL PROTECTED]> wrote: >>>> Rick, >>>> >>>> Yes, all of our packages are symmetrical speeds (same download and >>>> upload). >>>> So if they buy our 512k package, they get 512k down x 512k up all the >>>> time. >>>> They are not "dedicated" connections, but rather you get what you pay >>>> for >>>> connections. We still oversubscribe users on an AP, but only to the >>>> point >>>> where each AP is running around 60% capacity during peak times, thus >>>> leaving >>>> room for bursts, etc. We graph and monitor every single AP (over 200 of >>>> them) and every single user (bandwidth, packets, RSSI, etc.) so we >>>> always >>>> know what's happening on our network. >>>> >>>> We currently have three full OC-3 (155Mbps) dedicated connections to >>>> the >>>> backbone. On average, we pay $40/meg for bandwidth. Why is your upload >>>> price >>>> different than your download price? >>>> >>>> Travis >>>> Microserv >>>> >>>> RickG wrote: >>>> >>>> Travis, >>>> >>>> Nice work! Therefore, you are selling dedicated bandwidth to all of >>>> your customers. In other words, if all your customers run speed test >>>> at the same time they will get what their plan allows. If you dont >>>> mind, I have a few questions: >>>> Is the above scenario true for upload speed as well as download speed? >>>> What are you paying for your upstream connection? >>>> What type of upstream connection do you have? >>>> >>>> I'd like to be there and I keep hoping cheap bandwidth comes my way. >>>> When you are paying $150/meg for download and $400/meg for upload, the >>>> business model is tough. >>>> >>>> -RickG >>>> >>>> BTW: I'd take this offlist if you prefer but I think this is a problem >>>> that many us us small WISP's face. >>>> >>>> On Sat, Nov 1, 2008 at 9:30 PM, Travis Johnson <[EMAIL PROTECTED]> wrote: >>>> >>>> >>>> Every customer can get the speed they are paying for ANY time they run >>>> a >>>> speed test. We offer packages from 512k to 2.5meg for residential >>>> customers >>>> and they always get what they pay for (download AND upload, which is >>>> the >>>> same for all of our packages). >>>> >>>> Travis >>>> Microserv >>>> >>>> RickG wrote: >>>> >>>> Travis, >>>> >>>> If I understand this correctly, you have at least 1Mbps or higher of >>>> bandwidth for every customer? >>>> >>>> -RickG >>>> >>>> On Sat, Nov 1, 2008 at 12:34 PM, Travis Johnson <[EMAIL PROTECTED]> wrote: >>>> >>>> >>>> We deliver what the customers pay for. If they purchase a 1Mbps >>>> package, >>>> they get 1Mbps 24x7 (with no monthly bit caps). Personally I have never >>>> liked the "up to" speed packages... it's like going to Walmart and >>>> buying milk. You can pay $3 for a full 1 gallon, or you can pay $2 for >>>> "up to" a gallon (without really knowing how much you are going to get, >>>> but it will be somewhere between nothing and a full gallon). >>>> >>>> Travis >>>> Microserv >>>> >>>> Kurt Fankhauser wrote: >>>> >>>> >>>> Does anyone else here have customer/s that consume so much bandwidth >>>> that >>>> you have to throttle them down after say 5 minutes of downloading. And >>>> what >>>> do you tell them when they start complaining about the throttled down >>>> speed. >>>> (they don't know your throttling them though) >>>> >>>> >>>> >>>> Kurt Fankhauser >>>> WAVELINC >>>> P.O. Box 126 >>>> Bucyrus, OH 44820 >>>> 419-562-6405 >>>> www.wavelinc.com >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> ------------------------------------------------------------ >>>> -------------------- >>>> WISPA Wants You! 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