NETGEAR GS748T User Manual

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GS748T Smart Switch
Differentiated Services
The QoS feature contains Differentiated Services (DiffServ) support that allows traffic to be
classified into streams and given certain QoS treatment in accordance with defined per-hop
behaviors.
Standard IP-based networks are designed to provide “best effort” data delivery service. “Best
effort” service implies that the network delivers the data in a timely fashion, although there is
no guarantee that it will. During times of congestion, packets may be delayed, sent
sporadically, or dropped. For typical Internet applications, such as e-mail and file transfer, a
slight degradation in service is acceptable and in many cases unnoticeable. Conversely, any
degradation of service has undesirable effects on applications with strict timing requirements,
such as voice or multimedia.
Defining DiffServ
To use DiffServ for QoS, the Web pages accessible from the Differentiated Services menu
page must first be used to define the following categories and their criteria:
1. Class: Create classes and define class criteria.
2. Policy: Create policies, associate classes with policies, and define policy statements.
3. Service: Add a policy to an inbound interface
Packets are classified and processed based on defined criteria. The classification criteria is
defined by a class. The processing is defined by a policy's attributes. Policy attributes may be
defined on a per-class instance basis, and it is these attributes that are applied when a match
occurs. A policy can contain multiples classes. When the policy is active, the actions taken
depend on which class matches the packet.
Packet processing begins by testing the class match criteria for a packet. A policy is applied
to a packet when a class match within that policy is found.
The Differentiated Services menu page contains links to the various DiffServ configuration
and display features.
To display the page, click QoS  DiffServ. The Differentiated Services menu page contains
links to the following features:
• DiffServ Configuration
• Class Configuration
• IPv6 Class Configuration
• Policy Configuration
• Service Configuration
• Service Statistics

NETGEAR GS748T Specifications

General

Basic switching RJ-45 Ethernet ports quantity	48
MAC address table	16000 entries
Packet buffer memory	1.632 MB
Maximum data transfer rate	1 Gbit/s
Latency	20 µs
I/O ports	48 RJ-45 connectors for 10BASE-T, 100BASE-TX, and 1000BASE-T (Auto Uplink on all ports) 4 SFP slots for fiber Gigabit Ethernet modules
Dimensions (WxDxH)	440 x 260 x 43 mm
Power requirements	100-240VAC 50/60 Hz
Networking features	10BASE-T, 100BASE-TX, 1000BASE-T
Connectivity technology	Wired
Full duplex	Yes
Networking standards	IEEE 802.3x
Minimum system requirements	Category 5 network cables Network card for each PC Network software (e.g., Windows)
Mean time between failures (MTBF)	69930 h
Safety	UL listed (UL 1950)/cUL, IEC950/EN60950
LED indicators	Link, Power
Power consumption (typical)	70 W
Storage temperature (T-T)	-10 - 70 °C
Operating temperature (T-T)	0 - 40 °C
Operating relative humidity (H-H)	10 - 90 %

Weight and Dimensions

Weight	4000 g