An OVPN agent plays the role of its PE device in an OVPN.
It establishes, manages and maintains tunnels (VCs). To do
these operations, internal components are defined
corresponding to functional units as shown in figure 11: (1)
the access circuit allocation unit finds pairs of appropriate
ACs (in terms of QoS and transport technique) for a given VC
and reserves them, (2) the optical channel location unit
searches and locates an OC corresponding to the allocated pair
of ACs, and (3) the virtual circuit maintenance unit checks
and maintains the existence of VCs.
The well-balanced coordination between these functional
units will bring a high performance in dynamically managing
and providing VCs, along with changes of packet radio
channels in GPRS roaming. Each OVPN agent has a table of
OVPN components that it has connections with. This table
also contains the information about available resources in
these OVPN components. The functional units will access to
this table for speeding up their operations.