Quality of Service : an overview

2. Quality of Service : an overview

3. 787v structure

4. Thomson Gateways:Quite a bit of history in QOS

5. Release 4.1 • ATM QOS • Categories: • Unspecified Bit Rate • Variable Bit Rate - non real-time • Constant Bit Rate ATM QOS categories • ATM PVC shaping • Peak cell rate • Sustained Cell Rate • Maximum Burst Size • Connection Admission Control

6. Release 4.2 • ATM QOS • New Category: • Variable Bit Rate - real-time • ILMI 4.0 ATM Autoconfig (bridged connections only) • IPQOS: • Label classification, based on : • Source : interface, interface group, address range, port • Destination : address range, port • Type of Service byte : DiffServ Code Point, Precedence • …… • Label based forwarding

7. Release 4.2.7 • IPQOS: • AQM Queuing/ Scheduling • 4 queues with strict priority scheduling (residential products) • 6 queues strict priority / Weighted Fair Queueing (business) • Tail drop or Early (BLUE) packet discard • Propagation to lower priority queue • Congestion shaping : prevent real-time queue to starve other queues • Prioritize TCP ACK segments • Default mapping of VLAN user priority to/from internal class

8. Release 5.3 • ATM QOS book revision • IPQOS • Out-of-the-box DiffServ compliant • Weighted Round Robin scheduling support • TCP ACK optimization • IP rate limiting (Meters) • per label/interface (mark/drop) • Re-marking of IP TOS byte : Precedence / DSCP • Label classification extensions • Inheritance (using ALGs) • Bi-directional labels

9. Release 6.X • R6.1 • Layer 2 QOS • Bridged scenarios • Classification : VLAN tag (p-bits) or IP TOS (precedence, DSCP) • No use of labels • R6.2 • Application based labelling • System service manager configured QOS

10. Release 7.2 • Managed Ethernet Switch QOS • Classification +Queuing • 4 queues • Real-time queue on BCM5335M only • Ingress Rate Limiting • Egress Rate Shaping • Storm Control (=protection mechanism) • Ikanos CPE5 VDSL2 chipset QOS support • Main topic of this presentation

11. Release 8.1 • Bridge classification with bridge filters • TG784 Ethernet WAN buffer dimensioning • Ethernet path does not allow extensive support of QOS • Multi-link PPP (business)

12. Configuring QOSof the Ikanos CPE5

13. Introduction • How it works • How you configure it

14. How it works • Auto mode : • Enable / Disable QOS depending on sync rate • Classification criteria • P-bits in VLAN tag • IP Precedence • DSCP • Queueing : • 4 queues • Strict priority only

15. Auto mode • Below 10 Mbits/s sync rate : QOS enabled • Above 10 Mbits/s sync rate : QOS disabled • Threshold : • configurable • Default value = 10 Mbits/s (empirically determined value)

16. How you configure it • Configurable via CLI • All Commands in group :xdsl qos {787v}[xdsl qos]=>? Following commands are available : config : qos configuration Following command groups are available : class queue {787v}[xdsl qos]=>

17. How you configure it • Configure general parameters • Classify : Map QOS information fields into Internal Class • Queue : Map Internal Classes into Queues

18. Configure general parameters • QOS Operational state : enabled / disabled • Auto mode • Auto mode threshold {787v}[xdsl qos]=>:xdsl qos config qos state: enable qos automode: enable qos autothreshold: 100(x100kps) {787v}[xdsl qos]=>

19. Map QOS info fields to Internal Class • CLI commands located in group :xdsl qos class • Determine which QOS information field to use : • IPv4 TOS Byte : Precedence / DSCP value • P-bits (EPrio) • IPv4 TOS and EPrio are mutually exclusive :xdsl qos class config ethprio=enabled ipv4tos=disabled :xdsl qos class config ethprio=disabled ipv4tos=enabled • Map the QOS values to Internal class • TOS byte :xdsl qos class ipv4tos add .... • P-bits :xdsl qos class eprio config ....

20. Map TOS byte : CLI details • Map TOS byte [0-255] to internal class [0-7] :xdsl qos class ipv4tos add tos=0 tosrangeend=143 class=0 • Check :xdsl qos class ipv4tos list IPv4 TOS to Class Map Tos 0 TosRangeEnd 143 class 0 Tos 144 TosRangeEnd 144 class 7 Tos 145 TosRangeEnd 183 class 0 Tos 184 TosRangeEnd 184 class 7 Tos 185 TosRangeEnd 255 class 0

21. Map P-bits : CLI details • Map P-bits [0-7] to internal class [0-7] :xdsl qos class eprio configprioclass 00000000 • Check :xdsl qos class eprio list ethernet priority to class map pri[0] -> class 0 pri[1] -> class 0 pri[2] -> class 0 pri[3] -> class 0 pri[4] -> class 0 pri[5] -> class 0 pri[6] -> class 0 pri[7] -> class 0 These are the defaults

22. Map P-bits : example 1 • Map P-bits [0-7] to internal class [0-7] :xdsl qos class eprio configprioclass 76543210 Maps p-bit : 76543210 to class : 76543210 • Check :xdsl qos class eprio list ethernet priority to class map pri[0] -> class 0 pri[1] -> class 1 pri[2] -> class 2 pri[3] -> class 3 pri[4] -> class 4 pri[5] -> class 5 pri[6] -> class 6 pri[7] -> class 7

23. Map P-bits : example 2 • Map P-bits [0-7] to internal class [0-7] :xdsl qos class eprio config prioclass 01234567 Maps p-bit : 76543210 to class : 01234567 • Check :xdsl qos class eprio list ethernet priority to class map pri[0] -> class 7 pri[1] -> class 6 pri[2] -> class 5 pri[3] -> class 4 pri[4] -> class 3 pri[5] -> class 2 pri[6] -> class 1 pri[7] -> class 0

24. Map Internal Classes into Queues • CLI commands located in group :xdsl qos queue • Flow control is disabled in QOS Automode :xdsl qos queue number=(0-3) config flowcontrol=disabled • Map Internal Class to queue :xdsl qos queue map class=0 queue=0 drop=always • Verify with maplist :xdsl qos queue maplist

25. Example {787v}[xdsl qos queue]=>maplist xDSL qos queue map class queue rule 0 0 never 1 0 never 2 0 never 3 0 never 4 0 never 5 0 never 6 0 never 7 3 never

26. Thank you !