Control plane E-NNI interface

Overview

The basic functions of a control plane for an Automatically Switched Optical Network (ASON) are signaling and routing. Signaling is used to establish, maintain, and tear down end-to-end connections. Routing is used to select the most appropriate path between and within network domains. The data communications network for transferring this control plane information (signaling and routing messages) is called Signaling Communications Network (SCN).

In this release, the Alcatel-Lucent 1665 DMX supports the control plane E-NNI logical interface over inter-domain links for single node access domain configuration. The signaling protocol is RSVP-TE and routing protocol is OSPF-TE, based on OIF specifications.

E-NNI Functions

An example of a control plane network with Alcatel-Lucent 1665 DMX E-NNI connecting to an I-NNI capable core is shown below. In this example Alcatel-Lucent 1665 DMX NEs serve as edge nodes and Alcatel-Lucent 1675 LambdaUnite MSS NEs, or other vendors’ NEs, serve as core nodes. The core domain nodes support I-NNI within the domain and E-NNI between the domains.

Figure 3-40: Control plane network with Alcatel-Lucent 1665 DMX E-NNI connecting to an I-NNI capable core

The transport topology is SONET linear for the E-NNI, and mesh for the I-NNI. SONET linear topology supports unprotected and line 1+1 protection schemes. The mesh topology supports control plane-based protection schemes including 1+1 path (network) protection, dynamic reroute, and unprotected.

The primary function offered by such a network is the ability to create and delete end-to-end DS3, OCn, and Ethernet Private Line services between an ingress and an egress client-facing edge port. The connection setup and release are invoked by TL1 commands sent to the source edge node from OS, and carried out by the control plane (E-NNI and I-NNI). The connection can be either unidirectional or bi-directional. The signal rates for connections are restricted to STS-1, STS-3c, STS-12c STS-48c, , and STS-192c.

In Alcatel-Lucent 1665 DMX, an optical port is configured as TRADITIONAL, EDGE or ENNI, with TRADITIONAL as the default. The TRADITIONAL ports are outside of the control plane topology. The setup of cross connects associated with TRADITIONAL ports is managed as it was previous to the introduction of ENNI on Alcatel-Lucent 1665 DMX. The setup of cross connects associated with ENNI ports is controlled by the E-NNI control plane. The EDGE ports function as add/drop ports of the end-to-end control plane connections. A sub-network point (time slot) in an EDGE port can be used for either end-to-end control plane connections or traditional connections.

Table 3-1: Supported EDGE and ENNI ports

	EDGE port	E-NNI port
Port types	DS3, EC1, OC3, OC12, OC48, OC192 and Private Line VCG	OC3, OC12, OC48 and OC192 on the following packs: LNW55, LNW59, LNW62, and LNW82
Port protection	0x1 1+1 UPSR unprotected BLSR (Auto squelch map must be enabled)	0x1 1+1

Signaling Communications Network (SCN)

Control plane signaling (particularly E-NNI in this feature) and routing messages must be transferred between network entities by a dedicated IP based data communications network, which is referred to as Signaling Communications Network (SCN). It should be noted that the SCN topology is not necessarily the same as that of the transport network. Alcatel-Lucent 1665 DMX SCN supports both in-fiber (Line DCC) and out-of-fiber (LAN, specifically LAN-3) communication interfaces as signaling control channels. The inter-domain routing for SCN is based on manual routes.