QUALITY OF SERVICE · PART 1 packetlife.
net
Quality of Service Models
Best Effort · No QoS policies are implemented
Integrated Services (IntServ) · Resource Reservation Protocol (RSVP) is used to
reserve bandwidth per flow across all nodes in a path...
More
QUALITY OF SERVICE · PART 1 packetlife.
net
Quality of Service Models
Best Effort · No QoS policies are implemented
Integrated Services (IntServ) · Resource Reservation Protocol (RSVP) is used to
reserve bandwidth per flow across all nodes in a path
Differentiated Services (DiffServ) · Packets are individually classified and marked;
policy decisions are made independently at each node in a path
Layer 2 QoS Markings
Medium Name Type
Ethernet Class of Service (CoS) 3-bit 802.
1p field in 802.
1Q header
Frame Relay Discard Eligibility (DE) 1-bit drop eligibility flag
ATM Cell Loss Priority (CLP) 1-bit drop eligibility flag
MPLS Experimental Field (EXP) 3-bit field compatible with 802.
1p
IP QoS Markings
Precedence · The first three bits of the IP TOS field are evaluated; compatible with
Ethernet CoS and MPLS EXP values
DSCP · The first six bits of the IP TOS are evaluated to provide more granular
classification; backward-compatible with IP Precedence
QoS Flowchart
Terminology
Per-Hop Beha
Less