Prospect of multi-protocol Switching GMPLS

I. Introduction
With the continuous improvement of modern management methods, people's sense of time efficiency has been constantly strengthened. In the past, only people were not heard of their communication methods, affecting interpersonal communication.
Multi-Protocol Label Switching MPLS) combines the label-based Layer 2 technology with the layer-3 routing technology, and introduces a connection-oriented mechanism in a connectionless IP address, A short, fixed-length identifier called "tag" is used to forward a group. It is the most successful technology that integrates IP and ATM. With the implementation of MPLS, users get better network performance and better control over the network. However, MPLS also has limitations in providing bandwidth in the physical network. With the development of DWDM and optical switching, the supplier has the ability to change the bandwidth capacity on a given link. MPLS does not rely on these features. Therefore, if a user requests more bandwidth on a given link, no structure in MPLS can request this additional capacity to increase the bandwidth. Therefore, IETE defines the organization of the underlying Ethernet protocol. It uses MPLS extension to mask non-IP devices and proposes MPLSGMPLS. It is also called multi-protocol λ switching.
Ii. Similarities and Differences between GMPLS and MPLS 
GMPLS extends the MPLS protocol with the necessary structure. It controls not only routers, but also DWDM systems, ADM and optical crossover. You can use GMPLS to dynamically provide resources and provide necessary redundancy for multiple protection and recovery technologies.
This is important because GMPLS and MPLS are not network protocols. GMPLS is a signaling protocol used by a user device to establish or cancel a circuit for signals transmitted to another device. This is a world of difference from the network that must be artificially pinned by network users. In order to continue to develop on the basis of its IP address, GMPLS expands MPLS in several important ways. These changes affect the basic LSP feature of the label exchange channel, that is, the tag request and tag communication, the one-way feature of the tag exchange channel, the propagation of errors, and the information used for synchronization between the start tag exchange channel and the final tag exchange channel in the channel.
MPLS only processes the group switching function (psc) interface called GMPLS, while GMPLS adds four other types of interfaces. Layer 2 exchange function interfaces can transmit data based on frame and element content; time division multiplexing (TDM) function interfaces can transmit data based on data time slots; the switching function interface works on an independent wavelength or band just like the optical crossover interface, while the optical switching function interface works on an independent optical fiber.
These devices establish a tag exchange channel just like the devices in MPLS. The label exchange channel may be an IP group stream that has been routed, but it is easy to establish like other types of connections. The tag switching channel is a synchronous optical network SONET circuit, which must start and end with a synchronous optical network circuit. The establishment of a tag exchange channel involves the establishment of a tag exchange channel between all endpoints and the establishment of a request based on requirements. Data Streams of various data types on a link are rarely active, and a service only appears between several nodes, that is, the service is local, you can use this locality to establish a tag exchange channel based on requests to improve network scalability. GMLS establishes a tag exchange channel based on the request.
These different label switching channels benefit from the typical nesting of MPLS. In MPLS, grouped streams are pooled into larger streams. The same basic principle applies here, that is, the label exchange channel is regarded as a virtual representation of the physical structure. Therefore, the tag switching channel for the low-level synchronous optical network circuit SONET must be nested in the high-level synchronous optical network circuit. Similarly, the tag exchange channel running between optical switching cable interfaces FSC may include the switch function interface LSC, the tag exchange channel running between LSC may include the tag exchange channel running between TDM, followed by the L2 Switch interface L2SC), and finally the group exchange function interface PSC) the tag exchange channel between them.
In addition, GMPLS functions are similar to MPLS. Establish a tag exchange channel by sending a so-called PATH/LABEL request message by using a RSVP-TE or CR-LDP. The PATH/LABEL request message contains a common tag request, which is usually a specific routing object and a specific parameter for special technology. A common tag request is an additional part of GMPLS, it specifies the encoding type of the tag exchange channel and the Net Load type of the tag exchange channel. The encoding type indicates the technical type to consider, such as so net or GBIT Ethernet. The net load type of the label exchange channel indicates the information type carried by the Net Load of the label exchange channel.
Iii. Conclusion

Many challenges brought by current routing solutions have led to the efforts of data network equipment vendors to develop MPLS to merge optical networks and data networks. However, GMPLS can be used to extend MPLS to non-IP network components, such as cross-connector and plug-in multiplexing, indicating that all devices can access network information equally, the integration of optical networks and data networks has great applicability for radio and television networks.

Note: Li Jun, Senior Engineer of guangdian Information Network Center, Puyang City, Henan Province
Feng kaijiang, technician of guangdian Information Network Center, Puyang City, Henan Province