Specifies the value of the size of the hole in the port list
(usually 1 for US, 2 for Europe) that occurs at LivingstonOffs. This
optional parameter is only used if you are using Simultaneous-Use with a
NasType of Livingston in this Client clause. Defaults to the global value
of LivingstonOffs, see
Section 3.7.28. LivingstonHole.