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All Rights Reserved © Alcatel-Lucent 2007 Quality of Service-QOS Carlos Pereira Senior Communications Consultant Alcatel-Lucent 3 October 2007.

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Presentation on theme: "All Rights Reserved © Alcatel-Lucent 2007 Quality of Service-QOS Carlos Pereira Senior Communications Consultant Alcatel-Lucent 3 October 2007."— Presentation transcript:

1 All Rights Reserved © Alcatel-Lucent 2007 Quality of Service-QOS Carlos Pereira Senior Communications Consultant Alcatel-Lucent 3 October 2007

2 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September Hardware Queues Recommendations 4. Questions? 1.TCP/IP Where in the packet? User-Group

3 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 TCP/IP Protocol Stack VERS LEN Type of Service Total Length Identification Flags Fragment Offset TTL Protocol Header checksum source IP address destination IP address Options & padding DATA

4 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 IEEE 802.1Q/P/DSCP SFDSADA Type or Length DataCRC SFDSA (6) DA (6) Type VLAN (2) Data (1500) New FCS (4) VLAN ID (2) Standard Ethernet or Format: max. size 1518 bytes Basic 802.1Q Format: max. size 1522 bytes Fixed value identifying frame as a VLAN frame Variable value identifying VLAN that frame is for Including 3 bits reserver for CoS 802.1q frame is 4 bytes longer. CRC covers new longer frame Type or Length (2)

5 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 QOS -Trusted and Untrusted Ports > Trusted ports- preserve the P or DSCP settings in the Data flow. > Untrusted Ports strip QOS settings on Data flows to the port default, or QOS rule. > Trusted ports normally at Core of network, ( can also be at edge)

6 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 Queues The OmniSwitch 9000 and the OmniSwitch 6850 provide 8 Class of Service (CoS) Queues per egress port for prioritizing and scheduling traffic. - Traffic is assigned a CoS queue based on it matching a QoS policy rule that has priority assignment as an action of the rule. - Traffic received on a trusted port is assigned a CoS queue based on the DSCP value for IP traffic or based on the 802.1p value for non-IP traffic. - Traffic received on an untrusted port is assigned a QoS queue based on the default priority defined for the ingress port on which the traffic is received.

7 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September /9000 QOS Default 8 COS queues per egress port 802.1p used to select queues, TOS used for IP packets Strict priority for scheduling Configured by QoS ACL commands Condition Action Rules

8 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September /9000 QOS QoS Policies Classification on L1/L2/L3/L4 (IPV6 included) Enqueuing in one of the 8 COS queues Actions Drop frames Change queuing priority Update TOS/Diffserv and/or 802.1P priority tags 802.1p/TOS/Diffserv mapping Per COS max bandwidth (64K bps) Statistics (# of packets, # of bytes) Ingress policing / Egress shaping Multi-actions support

9 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 De-queuing-Egress Choice between 3 Algorithms Strict Priority Starting w/ highest priority first, Queues are serviced until empty Weighted Round Robin (packet based) Each queue to indicate how many packet to be serviced per interval Weight configurable 0-15 –Value of 0 to indicate the queue is to be considered Strict Priority Deficit Round Robin (bandwidth based) Each queue to indicate how many chunk (10KB) to be serviced per time interval Weight configurable 0-15 –Value of 0 to indicate the queue is to be considered Strict Priority

10 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 QOS LOG - have I got it right? policy rule Configures a policy rule on the switch. A rule is made up of a condition (for classifying incoming traffic) and an action (to be applied to outgoing traffic). policy rule rule_name [enable | disable] [precedence precedence] [condition condition] [action action] [validity period name | no vlaidity period] [save] [log [interval seconds]] [count {packets | bytes}] [trap | no trap]

11 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 QOS-CLI

12 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 Recommendations For a very good audio quality (close to the MOS score of 4) · Network round trip delay must be less than 150ms, · Jitter must be less than 20ms, · Packet loss must be less than 1%. For an acceptable audio quality (slightly superior to the MOS score of 3) · Network round trip delay must be less than 400ms, · Jitter must be less than 50ms, · Packet loss must be less than 3%. To meet these criteria and especially for maintaining voice quality, a VoIP call cannot experience more than one voice compression/ decompression operations (with G729A or 723.1) Fax over IP communications are very sensitive to packet loss. Therefore, the QoS profile for FoIP is: · Network round trip delay must be less than 400ms, · Jitter must be less than 50ms, · Packet loss must be less than 1%. These values correspond to worst-case scenarios because the redundancy mechanisms built into the fax machine mechanism is not taken account.

13 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007 Upcoming QOS enhancements Auto-Qos on NMS traffic - Auto NMS prioritizes NMS traffic to the switch and aims to alleviate access problems to the switch under DOS attacks. NMS traffic is identified as SSH(TCP Port 22), Telnet(TCP Port 23), Webview (HTTP Port 80) and SNMP(TCP port 161). Each of the above traffic patterns are switched into different queues to maximize the possibility of making the switch manageable/accessible via at least one method(viz. SSH, Telnet, Webview or SNMP Auto-Qos on CSBU appliances - By default the switch will trust all traffic detected as originating from CSBU IP phones. Detection is achieved by matching on the MAC address range used by CSBU IP phones. The MAC address range used by the CSBU IP phones are F-54-xx-xx F-64-xx-xx and F-66-xx-xx F-6F-xx-xx. Additionally the user can specify up-to 4 MACs or MAC ranges that need to be accorded the same QoS as the CSBU IP phones, by specifying the list in the special MAC group

14 All Rights Reserved © Alcatel-Lucent 2007 VF UK EDN RFI Presentation| September 2007


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