- Range Extender - 7 Updates
- Folded phone line can mess up DSL. - 2 Updates
| "pfjw@aol.com" <peterwieck33@gmail.com>: May 17 01:34PM -0700 Here is the scenario: We have installed remote power monitors on a primary feed (13,200 VAC) to a major hospital complex. It is measuring overall usage, demand, momentary usage (3 seconds for graphing purposes), peaks and surges. The idea is that it may be remotely monitored. As it happens, it is just a bit too far from the nearest node to be reliable. The installer purchased a range-extender (Cisco). The range extender will connect to the local WiFi just fine. Various "things" will connect to the range extender, just fine. Those things, when connected directly to a node operate just fine. Those things when attempting to connect through the range extender act blocked - "No Internet Connection". The system is unsecured, all security, firewalls and so forth must be software based and resident on the individual computers. Is there an easy or obvious solution? I am not the installer, I did not conceive or design the system, I am merely asking on his behalf based on what he is reporting. However, I will be one of the end-users. Thanks in advance! Peter Wieck Melrose Park, PA |
| Jeff Liebermann <jeffl@cruzio.com>: May 17 05:33PM -0700 On Thu, 17 May 2018 13:34:38 -0700 (PDT), "pfjw@aol.com" >just fine. Those things, when connected directly to a node operate just fine. >Those things when attempting to connect through the range extender act >blocked - "No Internet Connection". Wi-Fi range extenders, also known as store and forward repeaters, and range extenders, can be made to work, but only under limited conditions and topologies. My comments also apply to mesh networks and WDS networks, which are range extenders with the addition of an IP routing protocol. I've had quite a bit of experience ripping such abominations out and replacing them with other solutions. I can explain in detail, but I'm busy right now. Bug me in a few days. I once gave a talk on the subject of repeaters. Here are my disorganized notes on the topic: <http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/> To illustrate the effect, I took a simple 2.4 wireless link, and ran iPerf (actually Jperf) to measure the maximum throughput through the wireless link. Slides for 802.11g (2.4Ghz) without a range extender: <http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/802.11gn%20direct.jpg> The average throughput was 42 to 61 Mbits/sec average. I then powered on a pre-configured Linksys RE-2000 range extender and got this mess: <http://802.11junk.com/jeffl/FLUG-talk-2015-02-28/802.11gn%20through%20Netgear%20repeater.jpg> with an average throughput of zero to 24 Mbits/sec. If I turn off the range extender, and the speeds return to normal. You can easily reproduce the effect with a simple wireless router or access point, a client computah, and Jperf: <https://sourceforge.net/projects/iperf/files/jperf/jperf%202.0.0/> Be careful NOT to mix version 2 and 3 of iPerf and Jperf, which are incompatible. If you don't want to setup iPerf or Jperf, then just use ping. Without the repeater, just ping the local access point continously using some kind of ping that displays sequence numbers such as hrping: <http://www.cfos.de/en/ping/ping.htm> Ping away merrily and hopefully, you'll only have a few dropped packets. Then, turn on the repeater and ping away merrily again. If I'm right, you'll see a dramatic increase in dropped packets. Be sure to try the -M option (tx/rx times). >Is there an easy or obvious solution? Nope. The obvious start point is to get ride of generic store and forward repeaters. If you must use repeaters, build a proper mesh network, with proper routing, not something that just repeats EVERYTHING that it hears, which is little better than a jammer. Because there are to paths between the source and designation of every packed (direct and through the repeater), you're going to have collisions no matter how you build it. It's those collisions that are preventing reliable connections between devices. >I am not the installer, I did not conceive or design the system, >I am merely asking on his behalf based on what he is reporting. >However, I will be one of the end-users. The right answer is either large number of wireless access points, connected together with a switch, and not using an in-band backhaul. Take a look at how hotels and such handle a large number of access points and clients. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| Mike S <mscir@yahoo.com>: May 17 11:35PM -0700 > Thanks in advance! > Peter Wieck > Melrose Park, PA What's the make and model of the RE? |
| Look165 <look165@numericable.fr>: May 18 08:36AM +0200 Think of a PLC solution. |
| "J.B. Wood" <arl_123234@hotmail.com>: May 18 06:43AM -0400 > Here is the scenario: We have installed remote power monitors on a primary feed (13,200 VAC) to a major hospital complex. It is measuring overall usage, demand, momentary usage (3 seconds for graphing purposes), peaks and surges. The idea is that it may be remotely monitored. As it happens, it is just a bit too far from the nearest node to be reliable. Wow, I've never observed (above ground) anything like on a medium voltage (MV) AC distribution line. Just MV-LV distribution transformers, disconnect switches, circuit breakers and power factor correction caps. (We use 34.5/19.9 kV in my area). Extremely dangerous if mishandled. Sincerely, -- J. B. Wood e-mail: arl_123234@hotmail.com |
| "pfjw@aol.com" <peterwieck33@gmail.com>: May 18 09:15AM -0700 On Friday, May 18, 2018 at 2:35:30 AM UTC-4, Mike S wrote: > What's the make and model of the RE? Cisco-Linksys White device, two antenna, direct plug-in. Beyond which I do not know. Peter Wieck Melrose Park, PA |
| Jeff Liebermann <jeffl@cruzio.com>: May 18 09:39AM -0700 On Fri, 18 May 2018 09:15:42 -0700 (PDT), "pfjw@aol.com" >Beyond which I do not know. >Peter Wieck >Melrose Park, PA My guess(tm) would be Linksys RE6300, RE6400, or RE6700: <https://www.linksys.com/us/p/P-RE6300/> <https://www.linksys.com/us/p/P-RE6400/> <https://www.linksys.com/us/p/P-RE6700/> The problem with a wall mounted solution is that the antennas are in a terrible location for best coverage. They should be up as high as possible and away from any metal objects. These repeaters are made for installation convenience, not performance. Incidentally, if they say Cisco on the box, they're at least 3 years old. Belkin bought Linksys from Cisco in about 2013. The purchase of Belkin by Foxconn is awaiting regulatory approval. Someone mentioned power line networking. In a sub-station, you want as much air-gap isolation from the lines as possible. That leaves wireless, FSO (free space optics), and fiberoptics as the available options. -- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
| Tim <onelydad58@gmail.com>: May 18 04:39AM "NY" <me@privacy.net> wrote in > shorten it, what is the best way of arranging it so as to > avoid/minimise inductance? Is it better to arrange it in a zig-zag > rather than loops? At the frequencies DSL works at, inductance is not an issue. More of an issue is the fact that the wire was kinked. OP doesn't state how severely, but any kink is going to disrupt the twist pattern, and thus has the potential to interfere with transmission. The other factor is that if the kink is severe enough, it can cause partial reflectance of the signal in the reverse direction, potentially degradeing the signal to some extent. Since the DSL signal can approach 4mhz at the high end, skin effect is starting to enter the mix (barely, but there). This is going to be more noticable in solid core wire, since the single conductor is larger. In a stranded cable the multiple strands of smaller gauge will tend to lessen any impact from skin effect. I am going to assume that the wire is question is stranded as opposed to solid core conductors. In that case it is entirely possible that one or more of the multiple strands could actually have been broken by the kink, thus pretty much guaranteeing some reflection of the signal, with attending degradation. Granted, the effect of any of the conditions mentioned above will probably be slight, but they will be additive. The ideal solution would be to rewire the link to remove any excess wire. The only reason not to would be that the connection is considered to be only temporary, and even then I can make a case for not having any excess wire involved. |
| Mike S <mscir@yahoo.com>: May 17 11:36PM -0700 On 5/17/2018 9:39 PM, Tim wrote: > be to rewire the link to remove any excess wire. The only reason not to > would be that the connection is considered to be only temporary, and even > then I can make a case for not having any excess wire involved. I agree with previous posters that a bad connector, or a severe kink, sound like the most likely cause of the problem, in that order. |
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