Chapter 41: Vlan Forwarding With Qos - Avaya 1000 Series Configuration Manual

Chapter 41: VLAN Forwarding with QOS

Figure 45: VLAN Forwarding: Multi-Tenant Internet Access
The example above shows each multi-tenant customer represented as a separate VLAN on the Ethernet
switch. The connection in the customer office can be routed or bridged, depending on whether the provider
will be hosting customer applications at the POP. The Ethernet switch passes a VLAN trunk to the Secure
Router 1000 Series that forwards traffic, based on the VLAN tags, from this interface to the multilink bundle.
At the POP, tagged traffic is forwarded to a VLAN trunk port on the Ethernet switch. Routing between
customer VLANs is provided by the POP router using subinterfaces on the Gigabit Ethernet VLAN trunk.
The customer LAN subnet is extended all the way to the POP router making remote management of LAN
services (for example, DHCP, file servers. SMTP) possible.
The VLAN forwarding feature has the added benefit of being able to support non-IP traffic since all traffic is
forwarded based only on the Layer 2 VLAN tag. Although Avaya products do not communicate using non-
IP Layer 3 protocols, Secure Routers can forward these protocols.
The management VLAN feature provides in-band communication with the Secure Routers as well as the
Ethernet switches while remaining separate from customer traffic. The Secure Routers will examine the
destination IP address of any packets received on the management VLAN. If the destination is the Secure
Router, the address of the packet will be forwarded to the IP layer for local processing. If the address does
not match the address of the Secure Router, the packet will be forwarded to all interfaces configured for
the management VLAN with the exception of the interface where it was received. This allows all
transmission equipment to be managed in a single, flat VLAN.
When the Secure Router generates traffic on to the management VLAN, an ARP request is generated in
the direction of the VLAN's default route. If no default is configured, the ARP request will be generated
in all possible directions, and the interface receiving the response will be cached with the reply. The source
Avaya Secure Router 1000 Series Configuration Guide December 2010 263