Peering (NNI) Scenarios

 

This section describes specific scenarios involving the deployment of a 

 Session Border Controller within a Network-Network-Interface (NNI) across two carriers. The use cases described in this section illustrate the features from a user’s standpoint in the peering network.

The Peering or Network-Network Interface (NNI) refers to the service control interface between two or more IP networks.

acting as a peering connects these IP networks (carriers, sub-networks, long distance networks, etc.)  providing extensive routing capabilities and resource management.

in this configuration is also referred to as a Trunking (T-). In NNI deployment the call model does not support registration, refreshes etc. It supports only SIP calls conforming to a highly scalable model. The in peering deployment includes the following characteristics:

• Provides protection to the core both from malicious attacks and genuine but high traffic levels.
• Acts as a B2B UA to bridge/bond the ingress/egress SIP sessions while maintaining distinct networks at the lower layers.
• Provides facilities for protocol repair and adaptation.
• Polices/enforces bandwidth and resource utilization.
• Provides encryption services.
• Interwork between combinations of IPv6 and IPv4 for both media and signaling (does not translate between IP address types).
• Performs a key role in routing by selecting between different carriers.
• Provides transcoding functionality and normalizes traffic to the core since
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  sits at the edge (operator-dependent).
• Acts as IBCF in the IMS network environment.

Peering

enforces bilateral agreement by ensuring the correct aspects and interpretations of the SIP protocol between carriers.

• Ensuring each side receives the expected SIP headers, formats and content.
• Applying ingress/egress signaling filters.
• Ensuring transparency of SIP content (operators may use information the
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  does not understand).
• Providing SIP Message content manipulation functionality.