Cambium PTP 450 series, Руководство пользователя

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PTP 450 User Guide Data network planning
2-82
ptp-450 (July 2014)
This is the Translation Bridging feature, which you can enable in the General tab of the Configuration web page in
the BHM. When this feature is disabled, the setting of the Send Untranslated ARP parameter has no effect,
because all packets are forwarded untranslated (with the source MAC address intact).
See Address Resolution Protocol on Page 2-80.
Engineering VLANs
The radios support VLAN functionality as defined in the 802.1Q (Virtual LANs) specification, except for the
following aspects of that specification:

the following protocols:
o
Generic Attribute Registration Protocol (GARP) GARV
o
Spanning Tree Protocol (STP)
o
Multiple Spanning Tree Protocol (MSTP)
o
GARP Multicast Registration Protocol (GMRP)

embedded source routing (ERIF) in the 802.1Q header

multicast pruning

flooding unknown unicast frames in the downlink
As an additional exception, the BHM does not flood downward the unknown unicast frames to the BHS.
A VLAN configuration in Layer 2 establishes a logical group within the network. Each computer in the VLAN,
regardless of initial or eventual physical location, has access to the same data. For the network operator, this
provides flexibility in network segmentation, simpler management, and enhanced security.
Special case VLAN numbers
This system handles special case VLAN numbers according to IEEE specifications:
Table 41 Special case VLAN IDs
VLAN
Number
Purpose Usage Constraint
0
These packets have 802.1p priority, but are otherwise handled
as untagged.
Should not be used as a
management VLAN.
1
Although not noted as special case by IEEE specifications,
these packets identify traffic that was untagged upon ingress
into the BHS and should remain untagged upon egress. This
policy is hard-coded in the BHM.
Should not be used for system
VLAN traffic.
4095 This VLAN is reserved for internal use. Should not be used at all.
BHS membership in VLANs
With the supported VLAN functionality, the radios determine bridge forwarding on the basis of not only the
destination MAC address, but also the VLAN ID of the destination. This provides flexibility in how BHSs are used:

Each BHS can be a member in its own VLAN.

Each BHS can be in its own broadcast domain, such that only the radios that are members of the VLAN can see
broadcast and multicast traffic to and from the BHS.

The network operator can define a work group of BHSs, regardless of the BHM(s) to which they register.