Identifies the Transparent LAN on which this virtual port,
subscriber port and channel, is participating. This is a
12-bit value and is assigned by the EMS to ensure it is global
to all TLS services and TLS trunks which share any common
OSAPs or L2 switches. Note: It is prudent to keep the TlanId
unique within the carriers entire TLS service offering until
the carrier starts another 'TLS service domain'.
WARNING: TLAN ID of zero(0) is invalid. TlanId's 1..15 are
reserved for managment access. TlanId's 16..4095 are legal
values.