To determine which network ports (and, therefore, which network complexes) are eligible to transport traffic of individual SDPs, network-domain is provided. Network-domain information is then used for the sap-ingress queue allocation algorithm applied to VPLS SAPs. This algorithm is optimized in so that no sap-ingress queues are allocated if the specified port does not belong to the network-domain used in the specified VPLS. Also, sap-ingress queues are not allocated toward network ports (regardless of the network-domain membership) if the specified VPLS does not contain any SDPs.
Sap-ingress queue allocation considers the following:
SHG membership of individual SDPs
Network-domain definition under SDP to restrict the topology in which the specified SDP can be set-up
The implementation supports four network-domains within any VPLS.
Network-domain configuration at the SDP level is ignored when the SDP is used for Epipe or Ipipe bindings.
Network-domain configurations are irrelevant for Layer 3 services (Layer 3 VPN and IES services). Network-domain configurations can be defined in the base routing context and associated only with network interfaces in this context. Network domains are not applicable to loopback and system interfaces.
The network-domain information is only used for ingress VPLS sap queue-allocation. It is not considered by routing during SDP setup. Therefore, if the specified SDP is routed through network interfaces that are not part of the configured network domain, the packets are still forwarded, but their QoS and queuing behavior is based on default settings. Also, the packet does not appear in SAP statistics.
There is always one network-domain with the reserved name default. The interfaces always belongs to a default network-domain. It is possible to assign a specific interface to different user-defined network-domains. The loopback and system interfaces are also associated with the default network-domain at the creation. However, any attempt to associate those interfaces with any explicitly defined network-domain is blocked at the CLI level because there is no benefit for that association.
Any SDP can be assigned only to one network domain. If none is specified, the system assigns the default network-domain. This means that all SAPs in VPLS have queues reaching all fwd-complexes serving interfaces that belong to the same network-domains as the SDPs.
It is possible to assign or remove network-domain association of the interface/SDP without requiring deletion of the respective object.