Cisco WS-C2960S-24PD-L Software Guide - Page 216

Configuring the LRE Ports Chapter 7 Configuring the Switch Ports Table 7-1 LRE Profiles (continued) Profile Name LRE-10-5 LRE-5LL LRE-10LL LRE-15LL Profile Type Private Private Private Private LRE Link LRE Link Maximum Distance between Downstream Rate (Mbps) Upstream Rate (Mbps) the LRE Switch and LRE CPE 11.38 5.69 4101 ft (1250 m) 5.69 5.69 4921 ft (1500 m) 11.38 11.38 4101 ft (1250 m) 15.17 17.06 3445 ft (1050 m) Environmental Considerations for LRE Links The requirements of your LRE environment are based on these factors: • Maximum distance between the LRE switch and CPEs-LRE runs on Category 1, 2, and 3 structured and unstructured cable. The maximum distance supported on the LRE link is from 3500 to 5000 feet, depending on the profile. The higher the profile, the shorter the distance. In buildings where LRE traffic runs over bundled telco cabling, the maximum distance supported can be approximately 30 percent lower. Each terminated bridge tap in a room can further reduce LRE link distances by 300 feet. The quality of the cable, the size of the cable bundles, and cross talk within the bundle also can affect overall reach. • Site type-If your site has either a PBX providing telephone service throughout or has direct connections to the PSTN, you must identify the requirements of your local public telephone service provider. If your site is a single building (or is a connected set of buildings), consult a qualified electrician to ensure that the wiring conforms to the appropriate regulations for indoor circuits. If your site has separate buildings, you must determine how the buildings are cabled to each other. Where the wiring between the LRE switch and CPE leaves the building (or the armored conduits certified for inside wiring standards), it must be protected against lightning and shorts to high-voltage power. This protection might be provided by fuses or overvoltage protectors that comply with local regulations for outside wiring protection. Consult an expert in local telecommunications regulations for the details of this protection. • Age and type of wiring-You can estimate the type of wiring you have based on your site's age and type. - Newer installations less than 15 years old often use Category 3 cable in bundles of 25 pairs. There is no significant difference between 25-pair bundles and larger bundles. - Older installations (hotel, school, hospital, commercial-North America) 15 to 30 years old often use 24 AWG wiring with between 1 and 12 twists per foot (similar to Category 1) in bundles of 25 or more. - Older installations (residential-North America) 15 to 30 years old often use 26 AWG wiring with between 1 and 12 twists per foot (maybe type-2) in bundles of 100 or more. - Older installations (Europe) 15 to 30 years old often use 0.4 mm (similar to 26 AWG) wiring with between 1 and 12 twists per foot in bundles of 100 or more. 7-18 Catalyst 2900 Series XL and Catalyst 3500 Series XL Software Configuration Guide 78-6511-08