Cisco Cisco Aironet 1522 Lightweight Outdoor Mesh Access Point 디자인 가이드
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Cisco Aironet 1520, 1130, 1240 Series Wireless Mesh Access Points, Design and Deployment Guide, Release 6.0
OL-20213-01
Architecture Overview
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Wireless mesh data frame flow.
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AWPP exchanges.
Because the CAPWAP model is well known and the AWPP is a proprietary protocol, only the wireless
mesh data flow is described. The key to the wireless mesh data flow is the address fields of the 802.11
frames being sent between mesh access points.
mesh data flow is described. The key to the wireless mesh data flow is the address fields of the 802.11
frames being sent between mesh access points.
An 802.11 data frame can use up to four address fields: receiver, transmitter, destination, and source.
The standard frame from a WLAN client to an AP uses only three of these address fields because the
transmitter address and the source address are the same. However, in a WLAN bridging network, all four
address fields are used because the source of the frame might not the transmitter of the frame, because
the frame might have been generated by a device behind the transmitter.
The standard frame from a WLAN client to an AP uses only three of these address fields because the
transmitter address and the source address are the same. However, in a WLAN bridging network, all four
address fields are used because the source of the frame might not the transmitter of the frame, because
the frame might have been generated by a device behind the transmitter.
shows an example of this type of framing. The source address of the frame is MAP:03:70, the
destination address of this frame is the controller (the mesh network is operating in Layer 2 mode), the
transmitter address is MAP:D5:60, and the receiver address is RAP:03:40.
transmitter address is MAP:D5:60, and the receiver address is RAP:03:40.
Figure 17
Wireless Mesh Frame
As this frame is sent, the transmitter and receiver addresses change on a hop-by-hop basis. AWPP is used
to determine the receiver address at each hop. The transmitter address is known because it is the current
mesh access point. The source and destination addresses are the same over the entire path.
to determine the receiver address at each hop. The transmitter address is known because it is the current
mesh access point. The source and destination addresses are the same over the entire path.
If the RAP’s controller connection is Layer 3, the destination address for the frame is the default gateway
MAC address, because the MAP has already encapsulated the CAPWAP in the IP packet to send it to the
controller, and is using the standard IP behavior of using ARP to find the MAC address of the default
gateway.
MAC address, because the MAP has already encapsulated the CAPWAP in the IP packet to send it to the
controller, and is using the standard IP behavior of using ARP to find the MAC address of the default
gateway.
Each mesh access point within the mesh forms an CAPWAP session with a controller. WLAN traffic is
encapsulated inside CAPWAP and is mapped to a VLAN interface on the controller. Bridged Ethernet
traffic can be passed from each Ethernet interface on the mesh network and does not have to be mapped
to an interface on the controller. (See
encapsulated inside CAPWAP and is mapped to a VLAN interface on the controller. Bridged Ethernet
traffic can be passed from each Ethernet interface on the mesh network and does not have to be mapped
to an interface on the controller. (See
.)
Frame Control: 0x0308 (Normal)
Duration: 48
Receiver address: Airespac_53:03:40 (00:0b:85:53:03:40)
Transmitter address: Airspac_23:d5:60 (00:0b:85:23:d5:60)
Destination address: Airspac_40:23:a3 (00:0b:85:40:23:a3)
Fragment number: 0
Sequence number: 1410
Source address: Airspac_53:03:70 (00:0b:85:53:03:70)
Duration: 48
Receiver address: Airespac_53:03:40 (00:0b:85:53:03:40)
Transmitter address: Airspac_23:d5:60 (00:0b:85:23:d5:60)
Destination address: Airspac_40:23:a3 (00:0b:85:40:23:a3)
Fragment number: 0
Sequence number: 1410
Source address: Airspac_53:03:70 (00:0b:85:53:03:70)
148449
PAP:03:70
PAP:D5:60
PAP:03:40
Controller:23:a3