Port Redundancy

The SBC SWe Cloud currently supports maximum two packet (PKT) ports such as PKT0 and PKT1. If these PKT ports are virtual interfaces (ports from virtual Standard Switch (vSS) or virtual Distributed Switch (vDS) on VMware ESXi or ports from OVS on a KVM platform), port redundancy is supported through NIC teaming or bonding feature, which exists on respective hypervisor vSwitches. However, if these PKT ports are on SR-IOV interfaces, the port redundancy is not supported for PKT interfaces as hypervisor is by-passed in such NIC configuration.

The SBC SWe Cloud is enhanced to support port redundancy on SR-IOV interfaces based on the ICMP/ARP probing mechanism. This mechanism requires four PKT ports (SR-IOV VFs) configured on a SBC SWe Cloud instance, where each of these SR-IOV VFs may come from different physical NICs for better handling of connectivity failures due to physical NIC or physical link connected towards different physical switches.

The PKT ports are automatically configured in active-standby mode to provide port redundancy on active SBC SWe Cloud instance.  The PKT ports connected in standby SBC SWe Cloud instance remains in standby mode. The ICMPv4/v6 probing mechanism is used on active PKT ports, while ARP ACD/ICMPv6 NUD mechanism is used on standby ports.

Architecture

The following figure shows the SBC SWe Cloud redundancy model from a port-centric view using a secondary packet port for each primary packet port. A standby instance with its own primary and secondary packet ports is also depicted in this figure. On standby instance, all packet ports remains as standby. For example, in this diagram, the active SWe ports are PKT0_P and PKT1_S ports.

 

Terminology:

• Primary port: The PKT port that attempts to become active on an active SWe node. The packet ports on the SBC SWe (PKT0_P, PKT1_P) are considered as primary ports.
• Secondary port: The PKT port is designated as an alternative for a specific on-board primary port. The SBC SWe contains one secondary port for each primary port.

• Active port: The PKT port that is currently selected for use (For example, signaling, media); either a primary or a secondary port on an active SWe node.

   

  The port in the active state does not necessarily imply it is "up".

• Local standby port: A standby PKT port on an active SWe node provides redundancy protection to the currently active port.

• Standby port: A collective term for a local standby PKT port on an active SWe node or any packet port on an standby SWe node. Standby ports provides protection for active PKT ports.

• Enabled or Disabled ports: The PKT port may be administratively enabled or disabled. A PKT port that is disabled cannot be an active port.

   

  The PKT port's role (Primary/Secondary) is independent of the port's state (Active/Standby).
   

  For SBC SWe cloud platform, the Out of Service (OOS) sonusSbxNrsIpInterfaceOOSNotification alarm for Interface Group is generated only for logical ports pkt0 and pkt1. This alarm is not generated when physical ports (pkt0_p, pkt0_s, pkt1_p and pkt1_s) are down.

  For more information on port-redundancy CLI changes, refer to Link Detection Group and Link Monitoring in CLI (merged).