Vivotek FD8366-V - Page 89

VIVOTEK
User's Manual - 89
QoS/DSCP (the DiffServ model)
DSCP-ECN defines QoS at Layer 3 (Network Layer). The Differentiated Services (DiffServ) model is
based on packet marking and router queuing disciplines. The marking is done by adding a eld to the
IP header, called the DSCP (Differentiated Services Codepoint). This is a 6-bit field that provides 64
different class IDs. It gives an indication of how a given packet is to be forwarded, known as the Per Hop
Behavior (PHB). The PHB describes a particular service level in terms of bandwidth, queueing theory,
and dropping (discarding the packet) decisions. Routers at each network node classify packets according
to their DSCP value and give them a particular forwarding treatment; for example, how much bandwidth
to reserve for it.
Below are the setting options of DSCP (DiffServ Codepoint). Specify the DSCP value for each application
(0~63).
Note that different vendors of network devices might have different methodologies and unique
implementations. Shown below is a sample corresponding information from a Cisco switch. You should
enter a DSCP tag value according to the information provided by the network devices.
32
QoS Baseline/Technical Marketing Classication and Marking Recommendations
Application Layer3 Classication Layer 2 CoS/MPLS EXP
IPP PHB DSCP
IP Routing 6 CS6 48 6
Voice 5 EF 46 5
Interactive Video 4 AF41 34 4 QoS B
Streaming-Video 4 CS4 32 4
Locally-dened Mission-
Critical Data
3 - 25 3
Call-signaling 3 AF31/CS3 26/24 3
Transactional Data 2 AF21 18 2
Network Management 2 CS2 16 2
Bulk Data 1 AF11 10 1
Scavenger 1 CS1 8 1
Best Effort 0 0 0 0