H3C Technologies H3C Intelligent Management Center - Manual (Page 127)

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DSCP—Acronym for Differentiated Service Code Points, a packet-classification field in a packet's IP
header used by the DiffServ mechanism to identify incoming network traffic so that it can appropriately
manage it.
EF—Acronym for Expedited Forwarding, a network traffic behavior that provides low delay, low loss,
and low jitter characteristics that are suitable for voice, video and other real-time services. EF is one
category of behavior settings that you can specify for traffic classes in QoS. Expedited Forwarding is
detailed in the IEFT's RFC 3246 specification.
FIFO—Stand for first in, first out. In absence of any QoS or other queuing mechanisms, the standard way
that data traffic is handled on the network. All data packets are given the same priority and whatever
bandwidth is available. This of course can be problematic if a network's capacity is unable to handle all
incoming traffic.
QoS Policy—In QoSM, an association of a network service type, such as voice data, with a behavior. A
QoS policy can be deployed to multiple devices on a network to achieve the desired quality of service
for a particular network service.
GMP—Acronym for Group Management Protocol, sometimes also referred to as IGMP (Internet Group
Management Protocol), a standard defined in RFC1112 to specify how a host can register with a router
to receive specific multicast traffic. QoSM classifies GMP traffic among a group included in the built-in
CallSignaling classifier. GMP traffic is detected on the EDP 12000 port.
H323—A call-signaling protocol. QoSM classifies H323 protocol traffic among a group included in the
built-in CallSignaling classifier. H323 traffic is detected on both TCP and UDP ports 1719 and 1720. See
also Call Signaling.
ICMP—Acronym for Internet Control Message Protocol, which defines a type of packet that is used in
echo requests by the ping and hwping commands. ICMP can also be used to relay query messages.
ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange
data between systems, nor is it regularly employed by end-user network applications (with the exception
of some diagnostic tools like ping and traceroute). ICMP for Internet Protocol version 4 (IPv4) is also
known as ICMPv4. QoSM can only work with devices that support the hwping command.
IP-Prec—Short for IP Precedence, part of an 8-bit field in a data packet that can be used by the sending
host to specify the type of service (TOS) the packet should receive, for example, low delay or high
reliability. QoSM can use the IP-Prec setting to help with traffic classification and treatment.
Jitter—An undesirable deviation in the transfer rate of data over a network in relation to a clock source.
Jitter is most noticeable in voice applications, where it can cause noise and signal breakup. However,
jitter can also cause monitors to flicker, affect processor performance in computers, and even loss of data
during transmission.
Match Rule—An SQL query built into a QoS classifier, the purpose of which is to help identify the type
of network traffic flowing into a device.
MGCP—Acronym for Media Gateway Control Protocol, a call-signaling protocol for use in a centralized
call control architecture. MGCP is one layer of a suite of specifications for controlling VoIP networks and
clients. In QOSM, MGCP traffic can be classified, monitored, and controlled via QoS policy.
MIB—Acronym for Management Information Base, a virtual database that is used to manage nodes
(routers, switches, servers, etc.) on a network. During auto-discovery, QoSM examines the MIB module
on each device it detects on the network to see whether the device is support and what parameters the
device supports.
MPLS—Acronym for Multi-protocol Label Switching, a mechanism in telecommunications networks that
can quickly direct data from one node to the next based on virtual links, or paths. Because the nodes can