Distributed Layer 4 Call Processing

Host Managed

The host manages call processing on an CSP with a single service access point. If a connection is made between channels on different nodes, internal call control messaging is automatically sent between the nodes. This strategy allows for answer/release to propagate internally. It also allows for outseizure to initiate on a remote node (with the Connect message) so the host can manage calls as though the multi-node CSP were a single-chassis CSP.

When a connection is being made between two nodes (A, B) the host needs to send only a Connect message (or other connection management message) to Node A. Node A then establishes a connection with Node B using the Ethernet link. For routing messages between nodes like this, each node keeps a record of all Logical Span IDs in the CSP.

Important! When cross connecting spans or channels among nodes in an CSP, a separate message must be sent to each span or channel in the connection.

Example: Message 1: to Node 1, Cross Connect Channel A, B
Message 2: to Node 2, Cross Connect Channel B, A

When cross connecting spans or channels in the same node, only one message is required. But you can still use the two-message internodal method. Having one method (internodal) instead of two simplifies your application.

Example Message

This example shows the format of a Connect message that connects Span 0/Channel 0 on Node 1 to Span 65/Channel 0 on Node 4:

Table 10-2 API