ASON Protocol

Huawei OptiX GCP applies the link management protocol (LMP) as the link management protocol, OSPF-TE as the routing protocol, and RSVP-TE as the signaling protocol.

The following sections describe the functions of these protocols in an ASON network.

LMP

The LMP performs the following functions in an ASON network.

Creating and maintaining the control channels between adjacent nodes.

The following is the procedure of creating control channels.
- See Figure 1. When two adjacent ASON NEs start up, the LMP uses the OTN overheads or the DCC channels of the OSC to transmit messages. Node 1 transmits messages to Node 2, which performs the check to the received messages. If the messages pass the check, Node 2 returns messages to Node 1. If the messages do not pass the check, Node 2 returns a message to Node 1, indicating that the messages fail to pass the check. In this way, Node 2 waits for another check. Hence, a control channel between the two adjacent nodes is created.
- After the control channel is created, the two nodes store the information about the control channel and identify the control channel according to the ID.
Figure 1 Creating control channels
Verifying component links and TE links.

The following is the procedure of verifying TE Links.
- After the control channels are configured, an attribute consistency check is performed to the TE links to see if the information is identical at both ends of dynamically discovered or manually configured TE links. If the check succeeds, the OSPF protocol is used to flood the information of the TE links to the entire network.
- As shown in Figure 2, Node 1 transmits messages and the content to be checked to Node 2, which checks if it has the same information and returns the check result to Node 1.
Figure 2 Verifying TE links

OSPF-TE

The control plane of Huawei OptiX GCP applies the OSPF-TE, which is an extended protocol for OSPF, and performs the following functions.

Creates neighbor relations.
Creates and maintains control links.
Floods and collects the information about the control links on the control plane. According to the information, the protocol then generates the information about the routes that are required for forwarding messages on the control plane.
Floods and collects the information about the TE links on the transport plane. The protocol then generates the information about the network service topologies for service trail computation.

RSVP-TE

The RSVP-TE is a protocol for resource reservation. It is a type of signaling. In terms of traffic engineering, the RSVP is extended to RSVP-TE. The RSVP-TE mainly supports the following functions:

LSP creation
LSP deletion
LSP attribute modification
LSP rerouting
LSP trail optimization

Protocol Encryption

An external entity may modify the OSPF-TE protocol packets of the network, counterfeit a node of this network and transmit packets, or receive the packets transmitted by nodes in the network and repeat the attack. To prevent these network insecurities, the ASON provides the function to encrypt protocols. In an ASON domain, the RSVP and OSPF-TE protocols are encrypted for authentication.

The RSVP authentication is configured for nodes and the OSPF-TE authentication for interconnected interfaces (slots and optical interfaces).

The authentication can be non-authentication, plain text authentication or MD5 authentication.

Non-authentication: No authentication is required in this mode.
Plain text authentication: To verify the preset password. The authentication code must be a character string with no more than eight characters.
MD5 authentication: To verify the information that is encrypted by the MD5 algorithm. The authentication code must be a character string with no more than 64 characters.

The check succeeds only when the authentication modes and passwords of adjacent nodes are the same.