Re: [Asterisk-Users] OT: VoIP over bonded link
The above concern have been a major issue with telephone equipment (eg, central offices) and the telco's spend a significant amount of money burying very long rods in the ground and interconnectng them with the CO hardware using cables that are larger then 1/4 in diameter (don't remember the guage anymore). Every row of racks include the heavy ground cabling, and rack paint (etc) is often times scrapped off between racks to ensure a solid ground. They use special test equipment to actually measure the implementation. Yes - the last LEC I worked for grounded every single relay rack to the DC power plant ground with #6 cable. Might be overkill, but the cost of the cable versus a SONET shelf or DLC is definitely worth it. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
On Thursday 23 Feb 2006 20:34, Colin Anderson wrote: It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. Thanks for the reply. Unfortunately, the conduit for the provisioning of the new building is unsuitable for fibre (too many sharp bends) and we can't core out the concrete and put in a new conduit because of obstacles in the way that make laying new conduit impractical, so we are stuck with (existing) copper. We already have copper-to-copper connections of different types (electrical, security etc) between the buildings so a lightning strike is going to hose us no matter what. In that case, put opto-couplers in place to protect both ends. Fibre/ethernet transceivers at both ends with a short run of fibre will protect both ends. Lightening strikes are only one problem, look to see what happens when one building attempts to ground itself through the copper cable to the other side. I would also question the legality of connecting both building with what I assume is mains electricity. B -- http://www.mailtrap.org.uk/ ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
On Thursday 23 February 2006 13:57, Bob Goddard wrote: It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. That's a great rule of thumb, but the reality isn't quite so black and white. A direct lightning strike is not going to draw *any* significant current through the ethernet cable, as the moment you try to pull significant current, those cables will either open up or vaporize due to IR losses in such small gage wire. You'll have far more current draw through the (I'm assuming) metal conduit, which is already grounded. Yes, you may introduce grounding loops and these will cause other (sometimes significant) issues but they have all been solved before. The best solution is to simply take a pair of media converters with a fiber patch cable between them, space them out adequately and hope for the best. You're already going to have a conduction path through the power supplies of the media converters but with an isolation transformer and appropriate surge arrestors it's about as best as you are going to be able to do. Electrical faults are *easily* dealt with with appropriate fusing, surge arrestors, isolation and plain old common sense. I work in the power electronics industry; we regularly deal with lightning strikes (both direct and close call style) and while there is very little to protect you from a direct strike (we use station-class arrestors) there is a LOT you can do to minimize grounding or loop problems when wiring between buildings. Sometimes fiber just doesn't cut it, so no, it's not just stupid. -A. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. That's a great rule of thumb, but the reality isn't quite so black and white. A direct lightning strike is not going to draw *any* significant current through the ethernet cable, as the moment you try to pull significant current, those cables will either open up or vaporize due to IR losses in such small gage wire. You'll have far more current draw through the (I'm assuming) metal conduit, which is already grounded. The above is really not true with many production switches. Any form of static electricity (regardless of whether its sourced from lightning for people) can and have been known to blow the ethernet interface IC inside the switch. (I can have some of our customers ship a boat load of those to you if you want. You pay shipping. ;) Cabletron and SMC switches seem to be the worst, and SMC manufacturers a lot of entry level workgroup switches for other well known companies. Yes, you may introduce grounding loops and these will cause other (sometimes significant) issues but they have all been solved before. The best solution is to simply take a pair of media converters with a fiber patch cable between them, space them out adequately and hope for the best. You're already going to have a conduction path through the power supplies of the media converters but with an isolation transformer and appropriate surge arrestors it's about as best as you are going to be able to do. The above concern have been a major issue with telephone equipment (eg, central offices) and the telco's spend a significant amount of money burying very long rods in the ground and interconnectng them with the CO hardware using cables that are larger then 1/4 in diameter (don't remember the guage anymore). Every row of racks include the heavy ground cabling, and rack paint (etc) is often times scrapped off between racks to ensure a solid ground. They use special test equipment to actually measure the implementation. Historically, Florida locations have very poor grounding which is known to cause telco's issues for sure. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
On Thursday 23 Feb 2006 17:30, Colin Anderson wrote: I have to provision several dozen * users to a seperate building on our campus in the same subnet. Ordinarily, I'd just run a gigabit cat6 cable to another switch if it doesn't violate the 100 metre rule, but this building is several hundred metres away from my backbone. My only option for cabling to the remote building is copper. My plan is to provision them with a Linux bridge with 4 NIC's: 1 gigabit to the backbone, and three bonded together as a single interface (90 mbit aggregate), then plugged into this dealie: http://www.blackbox.com/Catalog/Detail.aspx?cid=425,1423,1424mid=4946 At the remote building, the reverse: another Linux box with 4 NIC's that de-aggregates the link to a gigabit connection on a switch, and then to the wall plates. I'm pretty sure this will work for data no problem, but I'm a little concerned about latency on a timing-sensitive applicaiton like VoIP. Anyone have experience with VoIP over bonded link? Is there a gotcha? Is this a stupid idea? On my whiteboard it looks fine! It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. B -- http://www.mailtrap.org.uk/ ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
I have to provision several dozen * users to a seperate building on our campus in the same subnet. Ordinarily, I'd just run a gigabit cat6 cable to another switch if it doesn't violate the 100 metre rule, but this building is several hundred metres away from my backbone. My only option for cabling to the remote building is copper. My plan is to provision them with a Linux bridge with 4 NIC's: 1 gigabit to the backbone, and three bonded together as a single interface (90 mbit aggregate), then plugged into this dealie: http://www.blackbox.com/Catalog/Detail.aspx?cid=425,1423,1424mid=4946 At the remote building, the reverse: another Linux box with 4 NIC's that de-aggregates the link to a gigabit connection on a switch, and then to the wall plates. I'm pretty sure this will work for data no problem, but I'm a little concerned about latency on a timing-sensitive applicaiton like VoIP. Anyone have experience with VoIP over bonded link? Is there a gotcha? Is this a stupid idea? On my whiteboard it looks fine! Some thoughts that you might want to consider... The vdsl box runs at speeds up to 15 meg. That translates into the longer the copper loop, the slower the speed. You'll probably want to accurately measure the copper loop length and translate that into some 'expected' speed. Probably won't be 15 meg, and whatever the documentation suggests, it will likely be a fair amount slower then that. Does the vdsl truly operate in a full duplex mode with equal bandwidth in either direction? We've worked with many corporations and institutions in over 40 states doing network performance assessments, and seldom (if ever) do bonded interfaces actually work the way that you might think they work. I've not spent any time with the linux bonding that you're considering, but you might want to better understand exactly how that works. E.g., some bonding actually functions at 'per packet' level, which implies the maximum speed of any single packet is the speed of one vdsl circuit. If one of the bonded circuits has errors, what impact does it have on the other three error-free circuits. (Its not uncommon for one interface to have very significant impact on all other interfaces.) If all of the above can be answered with positive thoughts, you'll still want to consider some form of QoS on those links to ensure the voip packets are not held in a queue. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
RE: [Asterisk-Users] OT: VoIP over bonded link
It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. Thanks for the reply. Unfortunately, the conduit for the provisioning of the new building is unsuitable for fibre (too many sharp bends) and we can't core out the concrete and put in a new conduit because of obstacles in the way that make laying new conduit impractical, so we are stuck with (existing) copper. We already have copper-to-copper connections of different types (electrical, security etc) between the buildings so a lightning strike is going to hose us no matter what. That aside, does anyone have opinions on my original question as to the suitability of bonded links for VoIP? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
Take a look at the Net2Net product which was purchased by Paradyne and then by Zhone (www.zhone.com). They make a unit that will bridge Ethernet over SDSL lines, 24 pairs will get you 50mbps through the link. It looks just like ethernet and VoIP will work fine over it. You can also check our RAD (www.rad.com) they have a bunch of long range ethernet extenders to run on existing copper. On Feb 23, 2006, at 3:34 PM, Colin Anderson wrote: It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. Thanks for the reply. Unfortunately, the conduit for the provisioning of the new building is unsuitable for fibre (too many sharp bends) and we can't core out the concrete and put in a new conduit because of obstacles in the way that make laying new conduit impractical, so we are stuck with (existing) copper. We already have copper-to-copper connections of different types (electrical, security etc) between the buildings so a lightning strike is going to hose us no matter what. That aside, does anyone have opinions on my original question as to the suitability of bonded links for VoIP? ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users -- Matthew S. Crocker Vice President Crocker Communications, Inc. Internet Division PO BOX 710 Greenfield, MA 01302-0710 http://www.crocker.com ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
Colin Anderson wrote: I have to provision several dozen * users to a seperate building on our campus in the same subnet. Ordinarily, I'd just run a gigabit cat6 cable to another switch if it doesn't violate the 100 metre rule, but this building is several hundred metres away from my backbone. My only option for cabling to the remote building is copper. My plan is to provision them with a Linux bridge with 4 NIC's: 1 gigabit to the backbone, and three bonded together as a single interface (90 mbit aggregate), then plugged into this dealie: http://www.blackbox.com/Catalog/Detail.aspx?cid=425,1423,1424mid=4946 At the remote building, the reverse: another Linux box with 4 NIC's that de-aggregates the link to a gigabit connection on a switch, and then to the wall plates. I'm pretty sure this will work for data no problem, but I'm a little concerned about latency on a timing-sensitive applicaiton like VoIP. Anyone have experience with VoIP over bonded link? Is there a gotcha? Is this a stupid idea? On my whiteboard it looks fine! If you have line of site, or even close, you can consider running VoIP over wireless bridges. We've run VoIP and network traffic over the Cisco 1300 and 1400 series bridges with no problems. They will support voice VLANs and qos. Thanks, Nick ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
Colin Anderson wrote: That aside, does anyone have opinions on my original question as to the suitability of bonded links for VoIP? It's not an issue. The bonded link acts just like any other link. ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [Asterisk-Users] OT: VoIP over bonded link
Colin Anderson a écrit : It's stupid. Don't ever connect 2 different building with copper. Just wait until you get some kind of lightening hit or electrical fault, but make sure you are no where near it. Use fibre. Thanks for the reply. Unfortunately, the conduit for the provisioning of the new building is unsuitable for fibre (too many sharp bends) and we can't core out the concrete and put in a new conduit because of obstacles in the way that make laying new conduit impractical, so we are stuck with (existing) copper. We already have copper-to-copper connections of different types (electrical, security etc) between the buildings so a lightning strike is going to hose us no matter what. That aside, does anyone have opinions on my original question as to the suitability of bonded links for VoIP? You might have a little bit of jitter, but that's what jitter buffer is all about. IMHO it would be fine for VoIP but as it has been pointed on the list it would be wise to prioritize correctly both ends of your aggregated link. PS: What about Wifi for your link? With a couple of well placed high-gain outdoor antennas you could cover the distance and have similar throughput... It could be significantly cheaper too! Cheers, Jean-Michel. -- Jean-Michel Hiver - http://ykoz.net/ Découvrez la Réunion des Technologies IP Telecom TEL: +262 (0)262 55 03 98 - RCS 434 273 330 SAINT PIERRE ___ --Bandwidth and Colocation provided by Easynews.com -- Asterisk-Users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
