With the rapid development of data services represented by the Internet, transport networks has evolved from transporting voice services to transporting data services predominantly and transporting voice services at the same time. In addition to Plesiochronous Digital Hierarchy (PDH) and Synchronous Digital Hierarchy (SDH) for voice services, the network connection services realized by transport networks further includes Ethernet, Asynchronous Transfer Mode (ATM), Frame Relay (FR) and so on for data services.
To realize the above network connection services, transport network elements usually include one or more line-side ports, enabling reliable transport from a plurality of transport channels to a line by multiplexing and demultiplexing; one or more tributary units (or, referred to as user units), responsible for connecting service signals on the client layer; and one or more cross-connect modules, responsible for establishing a cross-connect between the tributary unit and the line-side port and between two line-side ports, so as to establish an end-to-end network connection service. At the first and last nodes of a network connection service, various user-side services of the network connection service need to be adapted to the network connection via an adapter, so as to transport the user-side services.
In the prior art, no matter for a Permanent Connection (PC) established by a network management system or for a Soft Permanent Connection (SPC) established through a control plane, the establishment mechanism of the network connection service usually includes the following steps.
First of all, the management plane selects the type and number of network connections for the network connection service, and then selects a protocol adaptation stack from the user side to the network side in the network connection service.
Then, for a PC, the management plane establishes cross-connects for the network elements one by one so as to establish a network connection; or for an SPC, the network management system notifies the control plane to automatically establish the network connection.
Finally, the management plane accomplishes the adaptation of the ingress and egress network element from user-side services to the network connection.
In the above prior art, manual assignment is needed to configure the network connection supporting the network connection service and the adaptation stack from the user side to the network side in the network connection service; as a result, the time delay in the connection establishment is increased. If there are a large number of services, it is difficult to trace and eliminate a failure caused by an error in the configuration. Additionally, in the case that a Switched Connection (SC) is established via a User Network Interface (UNI), the above prior art where the network connection supporting the network connection service and the protocol adaptation stack from the user side to the network side in the network connection service are configured manually, is only applicable to a transport network with a single switching capability to establish a simple connection, such as an end-to-end connection of VC-4/VC-3. However, it is inapplicable to multi-service transport network conditions in which various switching capabilities are integrated together.