Hello, everyone!
In this post, I would like to share with you ASON DOMAIN necessary link.
Control Channels
The LMP creates and maintains the control channel between NEs. The control channel then provides a physical channel for the LMP packets. The control channels are classified into in-fiber and out-fiber control channels. The in-fiber control channels automatically find and use the D4-D12 bytes of DCC. The out-fiber control channel uses the Ethernet links, which should be manually configured.
The verification of component links and TE links can be performed if the control channels are available between two adjacent nodes.
At least one control channel should be present between two adjacent nodes. If several fibers exist between adjacent nodes, several control channels can be created.
Control Links
Control links are the communication links created for the communication between the protocol entities of NEs.
The open shortest path first (OSPF) control links are created and maintained by the OSPF protocol between two nodes. The information of the OSPF control links is flooded to the entire network. In this way, each NE can attain the information and then can form the control topology. The OSPF protocol of each NE computes the shortest control routes to each NE according to the control topology. The routes are then recorded in the forward table. The signaling RSVP then uses the routes to transmit message packets.
By default, control links are created in fibers. Control links can also be created outside fibers on the condition that the OSPF protocol of the Ethernet ports is enabled.
NOTE:
Although the control links and control channels are created in the DCC channels (D4-D12), they differ in terms of functions and are independent of each other. The OSPF-TE protocol floods the information about the control links to the entire network. Each ASON NE stores the information about the network-wide control links. The ASON NEs do not flood the information about the control channels to the entire network. Each NE only manages and stores the information about its own control channels.
TE Links
TE link is a traffic engineering link. The ASON NE sends its bandwidth information to other ASON NEs through the TE link to provide data for route computation. As a kind of resources, TE links can be regarded as fibers that have bandwidth information and protection attributes. However, the TE link does not correspond to a fiber respectively, because each fiber may correspond to many TE links. Currently, a fiber can be configured with one TE link.
The resources of a TE link can be classified into three types: non-protection resources, working resources, and protection resources.
If the multiplex section protection (MSP) is configured on some channels of a fiber, there are three types of resources. For example, if a 10 Gbit/s (64 VC4s) optical interface is configured with a 2.5 Gbit/s MSP, the TE links are allocated as follows:
1-8 VC4s are the working resources of the TE link.
33-40 VC4s are the protection resources of the TE link.
The rest of the VC4s are non-protection resources of the TE link.
If the MSP is configured completely in a fiber, there are only working and protection resources in this fiber.
If the MSP is not configured in a fiber, there are only non-protection resources in this fiber.
Component Links
A component link is a bandwidth unit smaller than a TE link. One TE link consists of only one component link in the actual ASON software.
NOTE:
Each ASON NE floods its own TE links to the whole network through OSPF-TE. Each NE obtains the network-wide TE links. ASON NEs do not flood their own component links to the whole network. They only manage and store their own component links.
That's all, I hope you like it.
Thank you!
