VPN ALL

Basic QoS Policy

The following is a basic QoS Policy for a branch office router to prioritize voice traffic . The assumption made is that the voice traffic is marked at source (i.e. ip phones). This is an example of a LLQ (Low Latency Queue) in which voice traffic is placed in a priority queue and all other traffic is placed in a WFQ (Weighted Fair Queue).

DMVPN is being used for connectivity back to the main office so we have to use the qos pre-classify command to ensure QoS is applied before data is encrypted and markings on the tunneled packets are preserved. Congestion management and avoidance is implement using a WFQ (Weighted Fair Queue) and WRED (Weighted Random Early Discard) for all non voice traffic.


class-map match-all VOICE
match ip dscp ef
class-map match-any CALL-SIGNALING
match ip dscp cs3
class-map match-any CRITICAL-DATA
match ip dscp cs6
match ip dscp af21 af22
match ip dscp cs2


policy-map WAN-EDGE
class VOICE
priority 256
class CALL-SIGNALING
bandwidth 32
class CRITICAL-DATA
bandwidth 64
class class-default
fair-queue

random-detect

interface Tunnel0
qos pre-classify
interface Dailer0
bandwidth 1500
service-policy output WAN-EDGE