[email protected] -- Click the “Transition Now” link for a live Web chat.
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Operation—continued
Product features—continued
IEEE802.1q VLAN tagging and double tagging
(Q in Q)
The 802.1Q specification establishes a standard method for inserting virtual LAN
(VLAN) membership information called tagging Ethernet frames to break large
networks into smaller parts or to address security concerns. Q in Q support simply
adds another layer of IEEE 802.1Q tag to the 802.1Q tagged packets that enter the
network. The purpose is to expand the VLAN space by tagging the tagged packets,
thus producing a "double-tagged" frame.
VLAN tagging can be configured to one of the following settings:
•
Normal = frames are unmodified when passing through the converter
•
Untag = all tagged frames will have their tag removed when passing through
converter
•
Tag = all untagged frames are tagged with the source port default VLAN ID
•
Double Tag = all egress frames are double tagged using the source port default
VLAN ID for the extra tag. This also enables ingress double tag removal.
Ingress:
a. Frame does not contain a tag, frame is not modified
b. Frame contains one 802.3ac tag, tag is removed
c. Frame contains two 802.3ac tags, the first tag is removed
Egress:
a. Frame is untagged, tag is added
b. Frame contains one 802.3ac tag, tag is added before the current one
becomes the frames new 802.3ac tag
IEEE802.1p QoS, IPv4 ToS/Diffserv, IPv6 Traffic class
The 802.1p specification is an extension of the IEEE 802.1Q standard and works in
tandem to define the prioritization of the Ethernet frame for traffic class expediting
and dynamic multicast filtering. IEEE 802.1p establishes eight levels of priority
(0
~ 7)
with 7 being the highest priority. Each egress Ethernet frame can be prioritized
using IEEE 802.1p
(MAC level)
Traffic Class, or IPV4 TOS and/or DiffServ and/or
IPV6 Traffic Class.
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24-Hour Technical Support: 1-800-260-1312 -- International: 00-1-952-941-7600
Operation—continued
Bandwidth allocation
It allows setting the bandwidth in varied increments, starting at 64 Kbps to full
bandwidth.
Rate limiting based on frame priorities can also be configured. Each higher priority
frame can be configured to get twice the bandwidth of lower priority frames; e.g.,
priority “3” frame configurations can get twice the bandwidth of priority “2”
frames.
Egress bandwidth allocation in 64Kbits/sec increments:
•
Rate limit all frames
Ingress bandwidth allocation in 64Kbits/sec increments with four filter selections:
•
Rate limit all frames
•
Rate limit multicast, flooded unicast, and broadcast
•
Rate limit multicast and broadcast
•
Rate limit broadcast
Port-Based VLAN
Allows secure traffic forwarding in one direction only.
RMON Counter on each port
RMON statistics such as packet size counters, collision errors, and packet type are
kept for each port.
Switch selectable speed
On unshielded twisted pair (UTP) when Auto-Negotiation is disabled, the speed can
be set in either software or hardware mode.
Virtual cable test (VCT) on UPT port
The VCT feature utilizes Time Domain Reflectometry (TDR) technology to
remotely and non-evasively diagnose the quality and characteristics of the attached
cable plant. Using this technology, the devices detect and report potential cabling
issues such as cable opens, cable shorts or any impedance mismatch in the cable
and then accurately report
(within one meter)
the distance of the fault. In addition,
the VCT technology will detect pair swaps, pair polarity reversal, and excessive pair
skew.
