Re: 5000' ethernet?
Elliot Finley efinley.li...@gmail.com wrote: A T1 can only run about 600 feet. Yes, that's right, 600 feet. When people talk about T1s running long distances, the reference to 'T1' is only the signalling at the end. In the middle, that T1 will be carried by other methods such as SONET over fiber for very long distances. For the last mile it will be carried on HDSL or similar technology. Or if it's a fairly long copper path, it can be carried on T-carrier. I suspect T-carrier is probably the technology I'm thinking of, which would have been sufficient to reach from practically anywhere to a telco switching center, even back in the mid-1970's when a T1 was considered blazingly fast (and neither fiber nor HDSL was at all widely used, if they even existed). ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David Kelly dke...@hiwaay.net wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? After reading (at least most of) the discussion that has arisen from this, I've had another thought which would use the wire already ordered -- although it does involve special hardware. Maybe you could set up what would amount to your own two-point telco: Option 1: Put a T1 frame-relay box at each end. I don't know how far a T1 can run without a booster of some sort, but I'd think it must be more than a mile or it would not have been commercially feasible. Option 2: Put an ordinary DSL modem at one end and a DSLAM at the other end. Again I'm not sure what the range is, but DSL used to be referred to as the solution for the last mile from the telco to the customer so it may be up to the job. AFAIK neither of these really needs the signal quality of Cat 5 -- they both should work just fine over Cat 3 -- but surely the higher grade wire can't hurt (and it may increase the usable DSL distance). ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Hi, AFAIK neither of these really needs the signal quality of Cat 5 -- they both should work just fine over Cat 3 -- but surely the higher grade wire can't hurt (and it may increase the usable DSL distance). I think I remember that the gauge of Ethernet cable is smaller than the one of phone cable: Ethernet cores are smaller, there can be an issue with the quality/strength of the signal. Of course DSL can go over one mile. Olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Hi, Am 2009-07-17 00:47:57, schrieb per...@pluto.rain.com: Option 2: Put an ordinary DSL modem at one end and a DSLAM at the other end. Again I'm not sure what the range is, but DSL used to be referred to as the solution for the last mile from the telco to the customer so it may be up to the job. I could recommend this too, because a Lucent Stinger IP DSLAM with 24 ports with 8 Mbit Downstream and 1 Mbit upstream cost arround 800 US$ and you can use inexpensive 2 wire (or multiple) telephone cable. The Lucent Stinger IP DSLAM support 8 Mbit in a distance of 6000ft and DSL lite with 384 kbit on 15000ft. Thanks, Greetings and nice Day/Evening Michelle Konzack Systemadministrator Tamay Dogan Network Debian GNU/Linux Consultant -- Linux-User #280138 with the Linux Counter, http://counter.li.org/ # Debian GNU/Linux Consultant # Michelle Konzack c/o Shared Office KabelBW ICQ #328449886 +49/177/9351947Blumenstasse 2 MSN LinuxMichi +33/6/61925193 77694 Kehl/Germany IRC #Debian (irc.icq.com) ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Option 2: Put an ordinary DSL modem at one end and a DSLAM at the other end. Again I'm not sure what the range is, but DSL used to be referred to as the solution for the last mile from the telco to the customer so it may be up to the job. I could recommend this too, because a Lucent Stinger IP DSLAM with 24 ports with 8 Mbit Downstream and 1 Mbit upstream cost arround 800 US$ and you can use inexpensive 2 wire (or multiple) telephone cable. The Lucent Stinger IP DSLAM support 8 Mbit in a distance of 6000ft and DSL lite with 384 kbit on 15000ft. If T1/E1 speed is enough, there are cards working with FreeBSD. If the CSU/DSU is on the card, I think you don't need extra equip and you have a symmetrical line. Should be OK for some miles with ordinary field telephone cable. You configure these cards almost like normal network cards if you run IP over them. Greetings, Heiner ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Check www.gnswireless.com (this from a satisfied customer) That said, I also use the method of placing mini ethernet switches or hubs (electrically a multiport repeater and damned hard to find now) every so often to reach distant parts of our warehouses. These are powered, of course. POE might work if you only needed one or two repeaters. mikel.k...@olivent.com wrote: 20090715202734.gh29...@tamay-dogan.net 20090715210752.ge16...@grumpy.dyndns.org From: Mikel mikel.k...@olivent.com Date: Wed, 15 Jul 2009 17:38:21 -0400 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit David, You can run upto 1.5 miles on a lx fiber based solution but will likely require a skilled installer to setup that much cable for you. Depending on your locale I am may be able to put connect you to a supplier. Have you considered a wireless direct beam solution? Especially considering the 'temporary' nature of this install. ___ Cheers, Mikel King CEO, Olivent Technologies follow-me http://twitter.com/mikelking .. Original Message ... On Wed, 15 Jul 2009 16:07:52 -0500 David Kelly dke...@hiwaay.net wrote: On Wed, Jul 15, 2009 at 10:27:35PM +0200, Michelle Konzack wrote: Hello David, Am 2009-07-15 14:47:18, schrieb David Kelly: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? I do not know hoe much a feet is in meters but AFAIK arround 0,3 which mean, you are talking about 1.5km or 1 mile ? Yes, roughly a mile which is 5280 feet. Maybe less, but no more than a mile. Won't really know until I get there and start running cable. There are inexpensive FiberOptic Transponder (I am using a bunch of it from Transmode for my CWDM 1GE and DWDM 10GE network) The 100 Mbit Transponder cost arround 600 Euro (each) and for your 5000 feets you need only an inexpensive FiberOptic cable. EVEN the cheapes one would transfer 1 Gbit at this distance. What I'm not (yet) seeing is a fiber optic transceiver listed with matching fiber optic cable. The transceivers seem inexpensive vs the cost of the cable. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? You have to use at least 3 Repeaters which NEED electricity. Do you know this? Yes, of course. 5000 feet CAT5, 3 Repeater plus electric installation cost more, then the FiberOptic Cable with two Transponder. And of course, no one can sniff traffic on FiberOptic and you have no worry about magnetic fields disturbing your 5000 feet... No one is going to sniff *this* one. Am not finding sources of fiber optic cable as easily as I can find fiber optic transceivers. 100baseT ethernet switches are about $25 each if one will serve as a regenerative repeater. Did I mention this is a temporary installation? -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org __ Scanned by Google Message Security - Leaving Seaman Paper ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Just for the archives: A T1 can only run about 600 feet. Yes, that's right, 600 feet. When people talk about T1s running long distances, the reference to 'T1' is only the signalling at the end. In the middle, that T1 will be carried by other methods such as SONET over fiber for very long distances. For the last mile it will be carried on HDSL or similar technology. Or if it's a fairly long copper path, it can be carried on T-carrier. But bottom line: The T1 signal that comes off of a CSU/DSU will reach about 600 feet. On Fri, Jul 17, 2009 at 1:47 AM, per...@pluto.rain.com wrote: David Kelly dke...@hiwaay.net wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? After reading (at least most of) the discussion that has arisen from this, I've had another thought which would use the wire already ordered -- although it does involve special hardware. Maybe you could set up what would amount to your own two-point telco: Option 1: Put a T1 frame-relay box at each end. I don't know how far a T1 can run without a booster of some sort, but I'd think it must be more than a mile or it would not have been commercially feasible. Option 2: Put an ordinary DSL modem at one end and a DSLAM at the other end. Again I'm not sure what the range is, but DSL used to be referred to as the solution for the last mile from the telco to the customer so it may be up to the job. AFAIK neither of these really needs the signal quality of Cat 5 -- they both should work just fine over Cat 3 -- but surely the higher grade wire can't hurt (and it may increase the usable DSL distance). ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David Kelly wrote: Since when does one have CSMA/CD when configured as full duplex? All full duplex ethernet connections are point to point, machine to machine, or machine to switch. There is no multiple access on full duplex. No chance of collision. You are running Ethernet, right? CSMA/CD is part of the Ethernet framing protocol. It is present in the protocol independent of simplex/duplex, etc. As such the timing windows contain non-infinite discreet value ranges. It is integral to Ethernet and does not get 'switched off' or disappear just because a link is full-duplex. So I'm thinking at 5,000' the problem is one of echo cancelation and signal loss, not one of ethernet protocol. These other electrical parameters are indeed important. Let's not forget near-end crosstalk, et al. If you have an oscilloscope and decide to try this, take a look at what's called the eye pattern. Then compare it with a circuit that is within correct functional parameters. You will immediately see a difference, and these are electrical effects of the medium. Excessive phase jitter and the NICs on either end will be unable to decode anything. As far as they are concerned there is only random 'noise' present. These physical parameters drive the limitations designed into the Ethernet protocol. There are maximum distances in fiber just as there are in copper. If we could simply ignore these things and do whatever we want why would they need exist in the first place? They exist because the propagation speed in the medium is not instantaneous. This makes the problem time. The furthest apart two nodes can be located is the time it takes for the smallest Ethernet packet to get from one end to the other. When a NIC transceiver is in the process of transmitting a packet it is also listening at the same time and calculating a CRC. It knows when a collision has occurred when the CRC does not match on both TX and RX. If they are too far apart in time, and both NICs key up at the same instant neither will ever know the collision has not yet occurred. Both will assume no collision has occurred and queue up the next packet, and so on and so forth. The problem is time, and time is directly related to the propagation speed of the medium. This relationship to time is present in the Ethernet protocol. The misconception present is that with full duplex there is no chance of collision meaning that CSMA/CD is somehow magically turned off or excluded. It is not. But none of this will matter. The electrical parameters of 5,000 feet of UTP will ensure that Ethernet doesn't even enter the picture as neither NIC on either end will ever be able to identify or decode any Ethernet frames. David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. Ain't that the truth? Hi Hi Hi. Just trying to hint at not wasting your time with something that won't work. By the way - I'm KD3FO 73 -Mike ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
On Thu, Jul 16, 2009 at 02:49:11AM -0400, Michael Powell wrote: David Kelly wrote: Since when does one have CSMA/CD when configured as full duplex? All full duplex ethernet connections are point to point, machine to machine, or machine to switch. There is no multiple access on full duplex. No chance of collision. You are running Ethernet, right? CSMA/CD is part of the Ethernet framing protocol. It is present in the protocol independent of simplex/duplex, etc. As such the timing windows contain non-infinite discreet value ranges. It is integral to Ethernet and does not get 'switched off' or disappear just because a link is full-duplex. Please explain more. I have coded ethernet and TCP/IP on 68HC12NE64 embedded microcontrollers and in full duplex the MAC doesn't listen nor wait before transmitting. There is no carrier detect but for the status from the PHY indicating a wire is present. These physical parameters drive the limitations designed into the Ethernet protocol. There are maximum distances in fiber just as there are in copper. If we could simply ignore these things and do whatever we want why would they need exist in the first place? Because not all ethernets are full duplex. Fiber transceivers are not smart devices the way switches are semi-smart and routers are fully smart. What I've seen of fiber transceivers they are no smarter than the old AUI to thick, thin, or 10baseT transceivers. So what is happening in your scenario where ethernet over fiber works but will not work over copper due to protocol timing? They exist because the propagation speed in the medium is not instantaneous. This makes the problem time. The furthest apart two nodes can be located is the time it takes for the smallest Ethernet packet to get from one end to the other. Why is the same not true with fiber? When a NIC transceiver is in the process of transmitting a packet it is also listening at the same time and calculating a CRC. It knows when a collision has occurred when the CRC does not match on both TX and RX. If they are too far apart in time, and both NICs key up at the same instant neither will ever know the collision has not yet occurred. A collision can never occur full duplex. When full duplex is enabled the receive verify function you describe is disabled. Both will assume no collision has occurred and queue up the next packet, and so on and so forth. The problem is time, and time is directly related to the propagation speed of the medium. This relationship to time is present in the Ethernet protocol. The misconception present is that with full duplex there is no chance of collision meaning that CSMA/CD is somehow magically turned off or excluded. But it is turned off. A full duplex switch does not echo the sender's bits back to the sender's receiver. A full duplex switch buffers the incoming bits, reads the header, selects an output port, and then starts sending the bits to that one port out of the FIFO. If it is a broadcast packet then most cheap switches will wait until all ports are available before sending the packet. Perhaps expensive switches will queue a copy of the broadcast to each port. Last sentences in last paragraph before See Also at http://en.wikipedia.org/wiki/Carrier_sense_multiple_access_with_collision_detection: Also, in Full Duplex Ethernet, collisions are impossible since data is transmitted and received on different wires, and each segment is connected directly to a switch. Therefore, CSMA/CD is not used on Full Duplex Ethernet networks. -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Michael Powell nightre...@verizon.net writes: You are running Ethernet, right? CSMA/CD is part of the Ethernet framing protocol. It is present in the protocol independent of simplex/duplex, etc. As such the timing windows contain non-infinite discreet value ranges. It is integral to Ethernet and does not get 'switched off' or disappear just because a link is full-duplex. I call your attention to the specification (IEEE 802.3) for Ethernet: 1.1.1 Basic concepts This standard provides for two distinct modes of operation: half duplex and full duplex. A given IEEE 802.3 instantiation operates in either half or full duplex mode at any one time. The term CSMA/CD MAC is used throughout this standard synonymously with 802.3 MAC, and may represent an instance of either a half duplex or full duplex mode data terminal equipment (DTE), even though full duplex mode DTEs do not implement the CSMA/CD algorithms traditionally used to arbitrate access to shared-media LANs. -- Lowell Gilbert, embedded/networking software engineer, Boston area http://be-well.ilk.org/~lowell/ ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David Kelly wrote: [snip] But it is turned off. A full duplex switch does not echo the sender's bits back to the sender's receiver. A full duplex switch buffers the incoming bits, reads the header, selects an output port, and then starts sending the bits to that one port out of the FIFO. If it is a broadcast packet then most cheap switches will wait until all ports are available before sending the packet. Perhaps expensive switches will queue a copy of the broadcast to each port. Last sentences in last paragraph before See Also at http://en.wikipedia.org/wiki/Carrier_sense_multiple_access_with_collision_detection: Also, in Full Duplex Ethernet, collisions are impossible since data is transmitted and received on different wires, and each segment is connected directly to a switch. Therefore, CSMA/CD is not used on Full Duplex Ethernet networks. Aha! I did not know this (obviously). Learn something new every day... Maybe I'm getting too old for this line of work. The brain just isn't working the way it once did. I'm a big proponent of RTFM, but usually am looking at new material instead of forgetting stuff I read +20yrs ago. Thanks for setting me straight guys, it's better to be in the know than the other way around. Maybe time to retire. I remember a Netware 4.12 install where the client had to run twice on full duplex because on the first attempt the acks came back too fast. Didn't do it on half. Same place I had no end of trouble trying to get a PC we used as a controller to connect a check processing transport to the back end servers. No matter what I did nothing worked. Turned out they had 600 feet of wire and forgotten to put a bridge in the middle that had been initially planned. -Mike ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
On Thu, Jul 16, 2009 at 04:33:24PM -0400, Michael Powell wrote: David Kelly wrote: Last sentences in last paragraph before See Also at http://en.wikipedia.org/wiki/Carrier_sense_multiple_access_with_collision_detection: Also, in Full Duplex Ethernet, collisions are impossible since data is transmitted and received on different wires, and each segment is connected directly to a switch. Therefore, CSMA/CD is not used on Full Duplex Ethernet networks. Aha! I did not know this (obviously). Learn something new every day... Maybe I'm getting too old for this line of work. The brain just isn't working the way it once did. I'm a big proponent of RTFM, but usually am looking at new material instead of forgetting stuff I read +20yrs ago. Thanks for setting me straight guys, it's better to be in the know than the other way around. Maybe time to retire. I like my job but can think of a lot of other funner things to be doing. There are a lot of trees out there with bark at handlebar height that needs to be loosened with my dirtbike! Can't afford to retire until AAPL hits $500. :-) As for RTFM read Lowell Gilbert's post in this thread where he points out its mentioned in only one place in the docs that they were using the term CSMA/CD MAC everywhere in the documentation no matter CSMA/CD didn't apply when the MAC was configured Full Duplex. So if you didn't fully grok the #include file you didn't have the proper macro definitions to rewrite what they were saying into what they meant. :-( -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' Ethernet?
Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? IIRC the classic Ethernet problem limiting the distance between the farthest points on a network had to do with timing and collisions. If these two NICs are configured full duplex then it seems one would have no idea how far away the other was due to timing issues. 100baseT uses lower power drivers than 10baseT, so perhaps 10baseT would work better. In any case, have boxes of cat5 on order so as to find out myself. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive Ethernet switch at each junction to serve as a regenerative repeater? I must say that all the information about Ethernet you have gotten about this has been quite interesting , but it seems a lot of people forgot that a simple answer is often the best answer. Basically you don't need to know all the info about timing and how Ethernet handles collisions. What you do need to know is that many people have research this, and that's why Cat5 cable standard has a maximum length of 100 meters or 328 feet, they have found this to be the maximum length that it reliably works. In order to go 5000 feet, you would actually need 15 repeaters. I have never tried to string that many switches or repeaters together though in my experience if you buy this many low end switches you will likely have one bad one in the bunch. Plus there's a lot of places you would need power, and if this is outside now you have to take the weather into account. It's unfortunate that wireless was ruled out as this would be the easiest method, and likely the cheapest. The next option I would look to is definitely fiber as you had mentioned before. I have only ordered fiber through our installer they come out string it polish and terminate the ends. Then we just plug in the patch cables. As for a supplier I checked some of the major vendors we use for cabling, they all offer only patch cables for fiber, my guess is that if you need to buy a spool, it would have to be from a whole sale outfit, and then you would need someone to put the ends on. Your best bet would be to search for data and communication cable installation services in your area. I would still quote wireless if it's feasible in the location as your customer (or management if this is for an in house operation) may change their mind after presented with the cost of a temporary fiber installation, and the problems a cat5 run would require overcoming. Hope this helps some, Thanks, Dean Weimer Network Administrator Orscheln Management Co Phone: (660) 269-3448 Fax: (660) 269-3950 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
5000' ethernet?
Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? IIRC the classic ethernet problem limiting the distance between the farthest points on a network had to do with timing and collisions. If these two NICs are configured full duplex then it seems one would have no idea how far away the other was due to timing issues. 100baseT uses lower power drivers than 10baseT, so perhaps 10baseT would work better. In any case, have boxes of cat5 on order so as to find out myself. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David Kelly wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? IIRC the classic ethernet problem limiting the distance between the farthest points on a network had to do with timing and collisions. If these two NICs are configured full duplex then it seems one would have no idea how far away the other was due to timing issues. 100baseT uses lower power drivers than 10baseT, so perhaps 10baseT would work better. In any case, have boxes of cat5 on order so as to find out myself. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? Aloha, About a year ago we had to do this and the solution was a fiber optic cable between the PC's and server room. Used 1000 Nic cards at each end. ~Al Plant - Honolulu, Hawaii - Phone: 808-284-2740 + http://hawaiidakine.com + http://freebsdinfo.org + + http://aloha50.net - Supporting - FreeBSD 6.* - 7.* - 8.* + email: n...@hdk5.net All that's really worth doing is what we do for others.- Lewis Carrol ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Hello David, Am 2009-07-15 14:47:18, schrieb David Kelly: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? I do not know hoe much a feet is in meters but AFAIK arround 0,3 which mean, you are talking about 1.5km or 1 mile ? I would say, NO chance with Ethernet... it is limited to 500 meters. 100baseT uses lower power drivers than 10baseT, so perhaps 10baseT would work better. There are inexpensive FiberOptic Transponder (I am using a bunch of it from Transmode for my CWDM 1GE and DWDM 10GE network) The 100 Mbit Transponder cost arround 600 Euro (each) and for your 5000 feets you need only an inexpensive FiberOptic cable. EVEN the cheapes one would transfer 1 Gbit at this distance. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? You have to use at least 3 Repeaters which NEED electricity. Do you know this? 5000 feet CAT5, 3 Repeater plus electric installation cost more, then the FiberOptic Cable with two Transponder. And of course, no one can sniff traffic on FiberOptic and you have no worry about magnetic fields disturbing your 5000 feet... Thanks, Greetings and nice Day/Evening Michelle Konzack Systemadministrator Tamay Dogan Network Debian GNU/Linux Consultant -- Linux-User #280138 with the Linux Counter, http://counter.li.org/ # Debian GNU/Linux Consultant # http://www.tamay-dogan.net/ Michelle Konzack http://www.can4linux.org/ c/o Vertriebsp. KabelBW http://www.flexray4linux.org/ Blumenstrasse 2 Jabber linux4miche...@jabber.ccc.de 77694 Kehl/Germany IRC #Debian (irc.icq.com) Tel. DE: +49 177 9351947 ICQ #328449886Tel. FR: +33 6 61925193 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
On Wed, Jul 15, 2009 at 10:27:35PM +0200, Michelle Konzack wrote: Hello David, Am 2009-07-15 14:47:18, schrieb David Kelly: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? I do not know hoe much a feet is in meters but AFAIK arround 0,3 which mean, you are talking about 1.5km or 1 mile ? Yes, roughly a mile which is 5280 feet. Maybe less, but no more than a mile. Won't really know until I get there and start running cable. There are inexpensive FiberOptic Transponder (I am using a bunch of it from Transmode for my CWDM 1GE and DWDM 10GE network) The 100 Mbit Transponder cost arround 600 Euro (each) and for your 5000 feets you need only an inexpensive FiberOptic cable. EVEN the cheapes one would transfer 1 Gbit at this distance. What I'm not (yet) seeing is a fiber optic transceiver listed with matching fiber optic cable. The transceivers seem inexpensive vs the cost of the cable. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? You have to use at least 3 Repeaters which NEED electricity. Do you know this? Yes, of course. 5000 feet CAT5, 3 Repeater plus electric installation cost more, then the FiberOptic Cable with two Transponder. And of course, no one can sniff traffic on FiberOptic and you have no worry about magnetic fields disturbing your 5000 feet... No one is going to sniff *this* one. Am not finding sources of fiber optic cable as easily as I can find fiber optic transceivers. 100baseT ethernet switches are about $25 each if one will serve as a regenerative repeater. Did I mention this is a temporary installation? -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
20090715202734.gh29...@tamay-dogan.net 20090715210752.ge16...@grumpy.dyndns.org From: Mikel mikel.k...@olivent.com Date: Wed, 15 Jul 2009 17:38:21 -0400 Content-type: text/plain; charset=US-ASCII Content-transfer-encoding: 7bit David, You can run upto 1.5 miles on a lx fiber based solution but will likely require a skilled installer to setup that much cable for you. Depending on your locale I am may be able to put connect you to a supplier. Have you considered a wireless direct beam solution? Especially considering the 'temporary' nature of this install. ___ Cheers, Mikel King CEO, Olivent Technologies follow-me http://twitter.com/mikelking .. Original Message ... On Wed, 15 Jul 2009 16:07:52 -0500 David Kelly dke...@hiwaay.net wrote: On Wed, Jul 15, 2009 at 10:27:35PM +0200, Michelle Konzack wrote: Hello David, Am 2009-07-15 14:47:18, schrieb David Kelly: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? I do not know hoe much a feet is in meters but AFAIK arround 0,3 which mean, you are talking about 1.5km or 1 mile ? Yes, roughly a mile which is 5280 feet. Maybe less, but no more than a mile. Won't really know until I get there and start running cable. There are inexpensive FiberOptic Transponder (I am using a bunch of it from Transmode for my CWDM 1GE and DWDM 10GE network) The 100 Mbit Transponder cost arround 600 Euro (each) and for your 5000 feets you need only an inexpensive FiberOptic cable. EVEN the cheapes one would transfer 1 Gbit at this distance. What I'm not (yet) seeing is a fiber optic transceiver listed with matching fiber optic cable. The transceivers seem inexpensive vs the cost of the cable. Are there any particular range extenders you have used and would recommend for making this task a sure thing on the first try? Perhaps I should put an inexpensive ethernet switch at each junction to serve as a regenerative repeater? You have to use at least 3 Repeaters which NEED electricity. Do you know this? Yes, of course. 5000 feet CAT5, 3 Repeater plus electric installation cost more, then the FiberOptic Cable with two Transponder. And of course, no one can sniff traffic on FiberOptic and you have no worry about magnetic fields disturbing your 5000 feet... No one is going to sniff *this* one. Am not finding sources of fiber optic cable as easily as I can find fiber optic transceivers. 100baseT ethernet switches are about $25 each if one will serve as a regenerative repeater. Did I mention this is a temporary installation? -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Hello *, Am 2009-07-15 17:38:33, schrieb mikel.k...@olivent.com: David, You can run upto 1.5 miles on a lx fiber based solution but will likely require a skilled installer to setup that much cable for you. Depending on your locale I am may be able to put connect you to a supplier. Have you considered a wireless direct beam solution? Especially considering the 'temporary' nature of this install. I could recommend the Alvarion BreezeNet B100 (or the B300). However, they are working in the 3.8 GHz and 5.0-5.8 GHz Band but have a range up to 40km (25miles). Here in Germany I have payed 3800 Euro for a complete 100 Mbit Bridge. Thanks, Greetings and nice Day/Evening Michelle Konzack Systemadministrator Tamay Dogan Network Debian GNU/Linux Consultant -- Linux-User #280138 with the Linux Counter, http://counter.li.org/ # Debian GNU/Linux Consultant # http://www.tamay-dogan.net/ Michelle Konzack http://www.can4linux.org/ c/o Vertriebsp. KabelBW http://www.flexray4linux.org/ Blumenstrasse 2 Jabber linux4miche...@jabber.ccc.de 77694 Kehl/Germany IRC #Debian (irc.icq.com) Tel. DE: +49 177 9351947 ICQ #328449886Tel. FR: +33 6 61925193 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David Kelly wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? IIRC the classic ethernet problem limiting the distance between the farthest points on a network had to do with timing and collisions. If these two NICs are configured full duplex then it seems one would have no idea how far away the other was due to timing issues. No. Ethernet uses a protocol design called Carrier Sense Multiple Access with Collision Detect, or CSMA/CD. The maximum lengths are indeed related to timing and the timing is a direct result of the propagation delay in the medium. The velocity factor will be some percentage of the speed of light. So the time it takes for the smallest Ethernet frame to get from the two farthest nodes will determine a window in which the two most distant nodes upon attempting a transmit can tell that a collision occurred and retransmit. The node(s) attempting to recover from a collision condition will each generate a random time back off in the hope that one will begin a packet transmission not at the same time as the other. The timing patterns of the frames are finite and not infinitely adjustable, e.g. there are limits which will declare a packet was not received and a resend is therefore required. What you will experience with 5,000 of Cat5 in full duplex is these limits will always be exceeded and the endpoints will believe no packets are arriving at their destinations and lock itself into a continual resend loop. When both ends do this you will have essentially either very little, or zero throughput. The max distance for UTP is 328 ft. Divide the 5,000 by 328 and it will tell you how many bridges, hubs, or switches you will need to regenerate the signal. You may find devices purporting to 'range extenders', but even these will have distance limitations requiring more than one. Foofaraw. 100baseT uses lower power drivers than 10baseT, so perhaps 10baseT would work better. In any case, have boxes of cat5 on order so as to find out myself. [snip] Sounds like a waste of time. Single mode fiber can support GB speeds some as far as 10km. Single mode fiber is what you want to look at for this distance. I'm not as current with long haul wireless links, but you may also find this could be done with the right wireless endpoints and good antennae, albeit you won't get the speed single mode fiber is capable of. -Mike ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
feet to metres [was: 5000' ethernet?]
On Wed 2009-07-15 22:27:35 UTC+0200, Michelle Konzack (bsd4miche...@tamay-dogan.net) wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? I do not know hoe much a feet is in meters but AFAIK arround 0,3 which mean, you are talking about 1.5km or 1 mile ? Just FYI, you can use FreeBSD's 'units' (/usr/bin/units) to convert feet to metres: $ units 5000 feet metres * 1524 There is also a more advanced version in /usr/ports/math/units/ that installs to /usr/local/bin/gunits. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
Hi, A general reply to many suggestions. So the time it takes for the smallest Ethernet frame to get from the two farthest nodes will determine a window in which the two most distant nodes upon attempting a transmit can tell that a collision occurred and retransmit. In a case of point-to-point UTP cable, there would be no collision though. But acknowledgement packets may take too long to reach the sending end, leading it to beleive the packet was lost and needs retransmission. I cannot rememebr if Ethernet have ACK packets. The max distance for UTP is 328 ft. Divide the 5,000 by 328 and it will tell you how many bridges, hubs, or switches you will need to regenerate the signal. You may find devices purporting to 'range extenders', but even these will have distance limitations requiring more than one. Foofaraw. That would make 14 hub/switches. I think I remember that the number of hubs is limited to 4 in between each end of the connection. I am not sure it is true also for switches. In any case, have boxes of cat5 on order so as to find out myself. You would need 5 boxes, the connections between each run of cable could cause too many loss, even if the timing was not an issue. As suggested by others, I would go for wireless ad it is the easiers to install if you have a line of sight. A complete wireless solution would range as little as $1500 including a couple of parabolic antennas with 18-20dB gain and the access point including power over Ethernet to power the antenna. Another solution, if you really don't need that much bandwidth, is to request an ADSL connection at each location and establish some kind of tunnel in-between the two boxes. For you this solution is zero cable installation, and very light configuration (ethernet over IP tunneling would allow you to extend your Ethernet layer 2 network across both end of the link). Of course you will be limited to the downlink bandwidth of your ADSL connection: if you get 20Mbps ADSL (that is 20Mpbs uplink/10Mbps down), you would have 10Mbps link. This solution should be quite cheap depending on your contract with your telephone company. As suggested before you could consider fiber optic, you could order a 2000 meters roll of underground outdoor fiber, with pig tail installed at each end. For a temporary use, you should not need any special precaution for installation: these fibers are usually shielded to support a truck to running on it... Or you can get the type of fiber designed for aerial usage, 8 shapped cable, including a suspension cable, and run it from tree to tree; but it's much much more installtion work, the cable tend to be heaviy... And you could get a couple of media converters (UTP to fiber) for $1000. Don't be afraid by the cost of fiber optic, most of the cost is labour to bury the fiber, it is not the cost of the cable itself. AFAIR, you can run 100Mbps on 2 kilometers of multimode fiber (multimode is cheaper I beleive). My choice would be: If I have the line of sight and the budget, I would go wireless, second choice being ADSL and third fiber optic. Bests, Olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
On Jul 15, 2009, at 9:25 PM, Olivier Nicole wrote: The max distance for UTP is 328 ft. Divide the 5,000 by 328 and it will tell you how many bridges, hubs, or switches you will need to regenerate the signal. You may find devices purporting to 'range extenders', but even these will have distance limitations requiring more than one. Foofaraw. That would make 14 hub/switches. I think I remember that the number of hubs is limited to 4 in between each end of the connection. I am not sure it is true also for switches. Hubs are simple analog repeaters. Switches are regenerative and buffered as the packet doesn't get resent until after the needed port is available. In any case, have boxes of cat5 on order so as to find out myself. You would need 5 boxes, the connections between each run of cable could cause too many loss, even if the timing was not an issue. Wire connections are not all that lossy. Meanwhile cat5 is useful for other things after this project is over. As suggested by others, I would go for wireless ad it is the easiers to install if you have a line of sight. Is my fault for not stating initially that the customer has ruled out any wireless option. Originally we were going to run a modest 50k bit/ sec wireless link. Another solution, if you really don't need that much bandwidth, is to request an ADSL connection at each location and establish some kind of tunnel in-between the two boxes. There are no phone lines at this location. As suggested before you could consider fiber optic, you could order a 2000 meters roll of underground outdoor fiber, with pig tail installed at each end. For a temporary use, you should not need any special precaution for installation: these fibers are usually shielded to support a truck to running on it... Or you can get the type of fiber designed for aerial usage, 8 shapped cable, including a suspension cable, and run it from tree to tree; but it's much much more installtion work, the cable tend to be heaviy... Sources? And you could get a couple of media converters (UTP to fiber) for $1000. Transceivers are easy to find. Matching cable has not been easy to find. Don't be afraid by the cost of fiber optic, most of the cost is labour to bury the fiber, it is not the cost of the cable itself. Not going to bury it. Is temporary for less than a week. -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
On Jul 15, 2009, at 5:41 PM, Michael Powell wrote: David Kelly wrote: Not directly FreeBSD related, but how much of a chance is there that two machines could communicate directly over 5,000 feet of cat5 with no special hardware? IIRC the classic ethernet problem limiting the distance between the farthest points on a network had to do with timing and collisions. If these two NICs are configured full duplex then it seems one would have no idea how far away the other was due to timing issues. No. Ethernet uses a protocol design called Carrier Sense Multiple Access with Collision Detect, or CSMA/CD. The maximum lengths are indeed related to timing and the timing is a direct result of the propagation delay in the medium. The velocity factor will be some percentage of the speed of light. Since when does one have CSMA/CD when configured as full duplex? All full duplex ethernet connections are point to point, machine to machine, or machine to switch. There is no multiple access on full duplex. No chance of collision. So I'm thinking at 5,000' the problem is one of echo cancelation and signal loss, not one of ethernet protocol. -- David Kelly N4HHE, dke...@hiwaay.net Whom computers would destroy, they must first drive mad. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
Re: 5000' ethernet?
David, You would need 5 boxes, the connections between each run of cable could cause too many loss, even if the timing was not an issue. Wire connections are not all that lossy. You would be surprised by the impedance missmatch tests made by cabling companies... Meanwhile cat5 is useful for other things after this project is over. And as you already ordered the cable, it is worth testing anyway. Is my fault for not stating initially that the customer has ruled out any wireless option. Originally we were going to run a modest 50k bit/ sec wireless link. OK, but you could have 10 Mbps, not only 50 Kbps, if the bandwidth is a limitation. As suggested before you could consider fiber optic, you could order a 2000 meters roll of underground outdoor fiber, with pig tail installed at each end. For a temporary use, you should not need any special precaution for installation: these fibers are usually shielded to support a truck to running on it... Or you can get the type of fiber designed for aerial usage, 8 shapped cable, including a suspension cable, and run it from tree to tree; but it's much much more installtion work, the cable tend to be heaviy... Sources? For the information? Holding a booth at an exhibition next to Krone booth, we got to talk a lot. For cable? I am afraid that, being in Thailand, my sources would charge you a very high transportation cost :) Krone is one brand, they manufacture mostly UTP cable and connectors, but I think they are associated with Belink for the fiber optic cable. I would try to contact a network installer in my area, they should be able to source fiber optic cable for you. Bests, olivier ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
