Nortel Networks Recording Equipment 1 User Manual
Voice over Wireless LAN Solution Guide
v1.0
December 2005
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Page 11
location. The three architectures can be combined as desired, so they are not mutually exclusive
choices.
choices.
The basic architectures are:
Distributed
Campus
Centralized
Campus
Branch
Office
The two AP connection types are:
Direct
connection
Distributed AP (DAP)
A direct connection is defined as an AP with a physical connection to a WLAN Security Switch
2300 and which is configured as an extension to the physical port. This AP does not require an IP
address to function. A Distributed AP is an AP with a logical connection to a WSS 2300 over a
Layer 2 (L2) or Layer 3 (L3) network. It is controlled just as if it were directly connected through
the Control and Provisioning Protocol (CAPP). Do not confuse a Distributed AP (DAP) with
Distributed Campus architecture, as they are different terms. A Distributed Campus can
implement either direct connections or DAPs or both. Likewise, a Centralized Campus usually
implements DAPs but can also have direct connections if the WSS is a model other than the
WSS 2380.
2300 and which is configured as an extension to the physical port. This AP does not require an IP
address to function. A Distributed AP is an AP with a logical connection to a WSS 2300 over a
Layer 2 (L2) or Layer 3 (L3) network. It is controlled just as if it were directly connected through
the Control and Provisioning Protocol (CAPP). Do not confuse a Distributed AP (DAP) with
Distributed Campus architecture, as they are different terms. A Distributed Campus can
implement either direct connections or DAPs or both. Likewise, a Centralized Campus usually
implements DAPs but can also have direct connections if the WSS is a model other than the
WSS 2380.
DAP connections are always implemented as an L3 tunnel between AP and security switch, and
require the DAP to receive an IP address from a DHCP server. This means that whether the
physical topology is a routed network or an L2 network the DAP connection is the same. Put
differently, DAPs operate the same way whether there are routers or switches between the AP
and WSS 2300. However, when the DAP is separated from the WSS 2300 by a routed network,
then either DNS or DHCP option 43 (Vendor Specific Information) is required for the DAP to learn
the IP address of a WSS 2300.
require the DAP to receive an IP address from a DHCP server. This means that whether the
physical topology is a routed network or an L2 network the DAP connection is the same. Put
differently, DAPs operate the same way whether there are routers or switches between the AP
and WSS 2300. However, when the DAP is separated from the WSS 2300 by a routed network,
then either DNS or DHCP option 43 (Vendor Specific Information) is required for the DAP to learn
the IP address of a WSS 2300.
2.2.1.1 Distributed
Campus
In a campus environment, there are generally two choices for placement of an AP controller (that
is, WSS)—at the edge (in a wiring closet) or in a central data center. The Distributed Campus
represents the former choice. With security switches at the edge, APs can be directly connected
and powered by the WSS 2300. This basic architecture is shown in Figure 1.
is, WSS)—at the edge (in a wiring closet) or in a central data center. The Distributed Campus
represents the former choice. With security switches at the edge, APs can be directly connected
and powered by the WSS 2300. This basic architecture is shown in Figure 1.
The WSS 2300 models most often deployed in this architecture are the WSS 2360 and WSS
2361. They have six PoE ports and two network ports and support up to 12 total APs. A full
complement of APs would require six to be powered by another device (injector or Power over
Ethernet [PoE] switch) and configured as DAPs. Typically, the APs utilize a mix of direct
connections and DAPs
2361. They have six PoE ports and two network ports and support up to 12 total APs. A full
complement of APs would require six to be powered by another device (injector or Power over
Ethernet [PoE] switch) and configured as DAPs. Typically, the APs utilize a mix of direct
connections and DAPs
The advantage of a Distributed Campus architecture is that it leverages the integrated PoE ports,
which can be of value to a network that does not have much PoE capability in the wiring closets.
It also allows some of the Authentication, Authorization, and Accounting (AAA) features to be
leveraged for wired users through the Wired Authentication feature. Lastly, support of third-party
APs tends to suggest a Distributed Campus architecture as well, because the third-party AP must
be L2 connected to the WSS 2300.
which can be of value to a network that does not have much PoE capability in the wiring closets.
It also allows some of the Authentication, Authorization, and Accounting (AAA) features to be
leveraged for wired users through the Wired Authentication feature. Lastly, support of third-party
APs tends to suggest a Distributed Campus architecture as well, because the third-party AP must
be L2 connected to the WSS 2300.