260 Configuring APs
NN47250-500 (Version 03.01)

Directly connected APs and distributed APs

To configure the WSS to support an AP, you must first determine how the AP will connect to the switch.
There are two types of AP to WSS connection: direct and distributed.
• In direct connection, an AP connects to one or two 10/100 ports on a WSS. The WSS port is then
configured specifically for a direct attachment to an AP. There is no intermediate networking equipment
between the WSS and AP and only one AP is connected to the WSS port. The WSS 10/100 port provides
PoE to the AP. The WSS also forwards data only to and from the configured AP on that port. The port
numbers on the WSS configured for directly attached APs reference a particular AP.
• An AP that is not directly connected to a WSS is considered a Distributed AP. There may be intermediate
Layer 2 switches or Layer 3 IP routers between the WSS and AP. The WSS may communicate to the
Distributed AP through any network port. (A network port is any port connecting the switch to other
networking devices, such as switches and routers, and it can also be configured for 802.1Q VLAN
tagging.) The WSS contains a configuration for a Distributed AP based on the AP’s serial number.
Similar to ports configured for directly connected APs, Distributed AP configurations are numbered and
can reference a particular AP. These numbered configurations do not, however, reference any physical
port.

Distributed AP network requirements

Because Distributed APs are not directly attached to a WSS, they require additional support from the network
in order to function. Information on the booting and operation sequence for Distributed APs is covered in the
section “Boot process for distributed APs” on page 268.
• Power—PoE must be provided on one of the Ethernet connections to the AP. Be sure to use a PoE
injection device that has been tested by Nortel. (Contact Nortel for information.) Providing PoE on both
of the Ethernet connections (on models that have two Ethernet ports) allows redundant PoE.
• DHCP—By default, a Distributed AP uses TCP/IP for communication, and relies on DHCP to obtain IP
parameters. Therefore, DHCP services must be available on the subnet that the AP is connected to. DHCP
must provide the following parameters to the AP:
●IP address
●Domain name
●DNS server address
●Default router address
• Static IP configuration—If DHCP is not available in the network, a Distributed AP can be configured
with static IP information that specifies its IP address, as well as the WSS uses as its boot device.
• DNS—If the intermediate network between the WSS and Distributed AP includes one or more IP routers,
create a wlan-switch.mynetwork.com entry on the DNS server. The entry needs to map one of these
names to the system IP address of the switch. If the subnet contains more than one WSS in the same
Mobility Domain, you can use the system IP address of any of the switches. (For redundancy, you can
create more than one DNS entry, and map each entry to a different WSS in the subnet.)
The DNS entry allows the AP to communicate with a WSS that is not on the AP’s subnet. If the
AP is unable to locate a WSS on the subnet it is connected to, the AP sends DNS requests to the
wlan-switch, where the DNS suffix for mynetwork.com is learned through DHCP.
●If only wlan-switch is defined in DNS, the AP contacts the WSS whose IP address is
returned for wlan-switch.