This object is used to specify the expected maximum
cable length for copper DSX ports such as T1, E1, and T3.
If a port does not use this feature, this object should
be notSupported (1).
T1 T-carrier ports should specify a max cable length between
0 to 655 feet using values len133 (2) through len655 (6).
T3 T-carrier, E1/E3 E-carrier and STS-1 SONET ports should use
either the value shortHaul (7) or longHaul (8).