The virtual containers and types

To carry signals, using virtual containers (VC: Virtual Container). In the VC that are sections overload (POH: Path Overhead), which are used by pointers. The transport of containers on STM 1 STM 16 done by TDM. The couple VC-pointer, called AU (Administrative Unit) can therefore to carry both synchronous signals. Depending on the speed, the units are two levels Possible AU3 and AU4. Containers are managed in the SDH transmission network, regardless of the signals they carry. This packaging is called adaptation.

Types

There are two types of virtual containers:

• The virtual containers of lower order (VC-11 VC-12, VC-2
and VC-3) which are carried in virtual containers
higher order.
• The virtual containers of higher order (VC-3 and VC-4)
are multiplexed to form the resulting signal.