[WISPA] Tower Problem - at my wits end
Over the last few months we have been fighting an intermittent problem on one of our towers.At seemingly random times, we will experience packet loss to customer equipment and/or large amounts of duplicate packets, anywhere from one dupe per 10 pings to 10+ dupes per ping. The tower has 3 sectors on it, and one horizontal omni. the sectors are on 1, 6, 11 and the horizontal is on 1. We are approximately 180 feet up the tower. The wireless cards are 200mW prism cards. I also know there is a FM radio station broadcasting off the tower, at 107.1, not sure about the .1. And Nortel Network has equipment on the tower also. The cat5 cable running up the tower is unshielded I believe. It was put up before I started with the company. The Access points are bridges plugged into a switch and then into a router. Normally this problem occurs during higher usage periods, an almost always stops at around 5pm, which made me assume we were overloading the AP(s), tonight though, I was seeing massive duplicates to one customer, and some duplicate packets to a bunch of other customers. The network load at the tower was minimal, right around 2mb/s. To test the sectors, I deauthorized all of the customers except the one with massive packet loss and turned off all sectors except theirs. I still saw alot of packet loss. Can poor tower grounding cause this? Is it something to do with the FM or Nortel equipment? I really don't think it is the routing equipment, since we have other towers that run fine and can push more through without an issue. Any suggestions or questions would be greatly appreciated. Ryan -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Tower Problem - at my wits end
Unsheilded cat 5 could be an issue if you are running 100Mbps on it as that is about the same frequency as the radio station. But, that should appear all the time. I had a backhaul link that would get double responses to pings much of the time. I think it was a multi-path issue as changing the height of one antenna reduced the problem. Fixed it by going to a different tower. If you are getting it more from one direction than another, I would suspect multi-path. 2 systems on the same channel could be a major problem. Your signal-to-noise ratio must be terrible on those 2 that are both on channel 1. That would cause lots of retranmissions (dropped packets.) Ryan Langseth wrote: Over the last few months we have been fighting an intermittent problem on one of our towers.At seemingly random times, we will experience packet loss to customer equipment and/or large amounts of duplicate packets, anywhere from one dupe per 10 pings to 10+ dupes per ping. The tower has 3 sectors on it, and one horizontal omni. the sectors are on 1, 6, 11 and the horizontal is on 1. We are approximately 180 feet up the tower. The wireless cards are 200mW prism cards. I also know there is a FM radio station broadcasting off the tower, at 107.1, not sure about the .1. And Nortel Network has equipment on the tower also. The cat5 cable running up the tower is unshielded I believe. It was put up before I started with the company. The Access points are bridges plugged into a switch and then into a router. Normally this problem occurs during higher usage periods, an almost always stops at around 5pm, which made me assume we were overloading the AP(s), tonight though, I was seeing massive duplicates to one customer, and some duplicate packets to a bunch of other customers. The network load at the tower was minimal, right around 2mb/s. To test the sectors, I deauthorized all of the customers except the one with massive packet loss and turned off all sectors except theirs. I still saw alot of packet loss. Can poor tower grounding cause this? Is it something to do with the FM or Nortel equipment? I really don't think it is the routing equipment, since we have other towers that run fine and can push more through without an issue. Any suggestions or questions would be greatly appreciated. Ryan --WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- Scott Reed Owner NewWays Wireless Networking Network Design, Installation and Administration www.nwwnet.net -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
Re: [WISPA] Tower Problem - at my wits end
On May 4, 2007, at 1:20 AM, Ryan Langseth wrote: Over the last few months we have been fighting an intermittent problem on one of our towers.At seemingly random times, we will experience packet loss to customer equipment and/or large amounts of duplicate packets, anywhere from one dupe per 10 pings to 10+ dupes per ping. The tower has 3 sectors on it, and one horizontal omni. the sectors are on 1, 6, 11 and the horizontal is on 1. We are approximately 180 feet up the tower. The wireless cards are 200mW prism cards. I also know there is a FM radio station broadcasting off the tower, at 107.1, not sure about the .1. And Nortel Network has equipment on the tower also. The cat5 cable running up the tower is unshielded I believe. It was put up before I started with the company. The Access points are bridges plugged into a switch and then into a router. Normally this problem occurs during higher usage periods, an almost always stops at around 5pm, which made me assume we were overloading the AP(s), tonight though, I was seeing massive duplicates to one customer, and some duplicate packets to a bunch of other customers. The network load at the tower was minimal, right around 2mb/s. EDIT: This should have been packet duplicates, not packet loss. To test the sectors, I deauthorized all of the customers except the one with massive packet loss and turned off all sectors except theirs. I still saw alot of packet loss. That should have said I still saw alot of packet duplicates I was a little tired when I sent this. Can poor tower grounding cause this? Is it something to do with the FM or Nortel equipment? I really don't think it is the routing equipment, since we have other towers that run fine and can push more through without an issue. Any suggestions or questions would be greatly appreciated. Ryan -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
