Nortel Meridian ITG Line 2.0 Description, Installation And Operation Manual page 25

The concentration of i2004s Telephones is made possible by dynamically
allocating a port (also referred to as a Physical TN) of the ITG card for a TDM
– i2004 call. All Meridian 1 speech path management is done with Physical
TNs instead of the Virtual TNs.
The choice of the port is not restricted to the ITG where the TPS handling that
particular i2004 is running. The port can be chosen among all the ITGs
dedicated to i2004s. The i2004s (Virtual TNs) are defined on Virtual
superloops.
A virtual superloop is a hybrid of real and phantom superloops. Like phantom
superloops, no hardware (for example, XPEC or line card) is used to define
and enable units on a virtual superloop. As with real superloops, virtual
superloops use the time slot map to handle i2004 Internet Telephone (Virtual
TNs) to i2004 Internet Telephone calls.
Terminal proxy server (TPS) description
The TPS maintains a count of the number of sets registered to the card. Each
node has one active master. The active master broadcasts to all ITG cards
requesting a response if it has room for another set. 96 is the maximum
number of sets per card.
The Election function uses a selection process to determine the node's master.
The Census function determines the ITG cards within a node.
Virtual Terminal Manager (VTM) description
The Virtual Terminal Manager:
• arbitrates application access to the i2004s.
• manages all the sets between the applications and the stimulus messaging
to the set.
• maintains context sensitive states of the set (for example, display or lamp
state).
• isolates set-specific information from the applications (for example, the
number of display lines, number of characters for each display line, tone
frequency and cadence parameters).
ITG Line 2.0/i2004 Internet Telephone Description, Installation, and Operation
Description Page 25 of 302