CUPS Traffic Handling

CUPS is essentially the separation of the control plane and user plane network functions. Due to this, the network element functions and the Gigamon devices (or nodes) that constitute the traffic visibility and analytics fabric managed by GigaVUE‑FM, for Mobility Solutions are generally spread across multiple geographically dispersed data centers called sites.

A site is a collection of the following:

  • Network element functions
  • Traffic access points for interfaces of such network element functions
  • Visibility and analytics fabric (VAF) nodes
  • Traffic monitoring or analysis tool devices (called probes) that are locally connected without using any IP routed tunnels

The Gigamon VAF nodes supporting a given site are typically arranged into a constellation of clusters connected by inter-cluster links.

The VAF nodes are collocated with the mobility network element functions for local-to-the-site traffic interception and usually with traffic monitoring or analysis probes for local-to-the-site traffic forwarding. Network traffic visibility is accomplished by using fabric maps to guide traffic received from the access points on any network port of the constellation through any GigaSMART engine available within the constellation to any tool port or GigaStream of the constellation. The nodes collocated at the control plane sites are referred to as Control Plane Network (CPN) and the nodes collocated at the user plane sites are referred as User Plane Network (UPN).

The distributed nature of the network and the VAF leads to the challenge of synchronizing the traffic forwarding to the tools spread over multiple sites and hence synchronizing CPNs and UPNs involved in handling and forwarding sessions in a subscriber-aware manner. To manage these challenges, the Control and User plane session correlation mechanism performs the following:

  • CPN/UPN Tool Forwarding Synchronization: Synchronizes the traffic forwarding to the tools across all CPNs and UPNs.
  • CPN-to-UPN Dynamic Mapping: Provides an efficient way of sending CPN-established session information updates to the specific UPNs where the established User Plane traffic sessions are anticipated.