I have two des-1005d network switches. i want to communicate betwwen them with a cat5e cable. the cable is made as cross through and distance is about 70 meters. with one switch pc is connected and at other end ADSL modem is connected. Now led indicator of both switches is blinking with about 1 to 2 sec interval and there is no communication. BUT if we reduce cable length b/w two switches, everything gets normal either with cross or straight through cable. please guide me about this problem. thanks and regards Muhammad Jamil Awan

Max distance for Cat5e cable is about 100M, but that is the best case scenario, essentially a straight line, down a building. If you have any kind of interference, like flourescent lighting, high voltage lines running parallel to the ethernet cable, the distance will be much less than 100M. Although it looks like you have 60 feet to spare, anything interfering with the cables will cut the signal down. Try to move the switches closer together, make the cable from pc to switch longer and ADSL modem to switch longer and cable between switches shorter. Use a known good straight through ethernet cable, as modern switches don't require crossover cables.

From Wikipedia: http://en.wikipedia.org/wiki/Category_5e#Maximum_cable_segment_length

According to the ANSI/TIA/EIA standard for category 5e cable, (TIA/EIA 568-5-A[5]) the maximum length for a cable segment is 100 meters (328 feet). If longer runs are required, the use of active hardware such as a repeater, or a switch, is necessary.[6] [7] This 100 meter limit is all inclusive. According to some authors,[who?] the practical limit for permanently installed cable is about 90 meters, leaving 5 meters at each end for the patch cables that connect the end equipment to the wall panel.

Hope this helps.