QoS in PPPoE Quality of Service in the Point-to-Point Protocol over Ethernet Master’s Thesis Patrik Lahti KTH, Telia Research AB
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 2
Quality of Service • Enhance the network • IP with the intelligence to – Differentiated Services treat traffic according – Integrated Services to application • Ethernet requirements. – Priorities (802.1p) – Delay – Subnet Bandwidth – Delay variation Manager – Loss – Others... 25/10/2000 QoS in PPPoE 3
Point-to-Point Protocol over Ethernet • Purpose – To set up Client to Access Concentrator relationship – Encapsulate PPP, and multiplex multiple PPPoE sessions • Operation – Simple Active discovery – Session 25/10/2000 QoS in PPPoE 4
Mulitcast PADI, w Service-Name Client AC Unicast PADO, w Service-Name(s) PPP/PPPoE & AC-Name Unicast PADO, w Service-Name(s) & AC-Name *) Client AC LCP Unicast PADR, w Service-Name Auth Unicast PADS, w Service-Name & Session ID IPCP PPP session Stage Unicast PADT, w Session ID **) IP data t *) There may be multiple ACs answering with a PADO **) May be sent by either side 25/10/2000 QoS in PPPoE 5
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 6
Background IP IP IP PPP PPP ? PPPoE Sw Sw PPPoE Ethernet Ethernet Ethernet Ethernet Ethernet Ethernet & Model Physical Physical Physical Physical Physical Physical Customer Ethernet Ethernet IP-access Equipment Switch Switch Node STB IPT 10Mbps Ethernet • CPN 100Mbps Ethernet Ethernet Sw • VLAN PC Ethernet Sw 1Gbps Ethernet • IP Access Node Ethernet Sw • New Services => QoS IP-access IP Network Node • NSP selection AAA DSLAM • Protocols ATM 10Mbps Ethernet STB IPT ADSL . ADSL PC 25/10/2000 QoS in PPPoE 7
Why PPP/PPPoE? + NSP selection - Overhead and Connection delay(?) + IP address allocation - Software update for Clients + Reuse of Legacy Equipment - QoS issues unresolved (?) + Unified Model (Bridged ADSL) + Familiar to users + Per user access control and billing 25/10/2000 QoS in PPPoE 8
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 9
Problem Definition • With what methods can QoS be support be introduced in PPPoE? • Can services with different QoS requirements be multiplexed in one PPPoE session? • Does PPP/PPPoE cope with loss, delay, reordering, and duplication? • How is performance affected by PPP/PPPoE? • What issues have to be addressed in the IP access? 25/10/2000 QoS in PPPoE 10
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 11
QoS in the PPPoE-based Broadband IP Access. • IP Differentiated Services – Guaranteed Service – Low Delay – Low Loss – Best Effort • Ethernet User Priorities, 802.1p – 7 Traffic types: NC, Voice, Video, Controlled Load, Excellent Effort, BE, Background • PPP/PPPoE? 25/10/2000 QoS in PPPoE 12
QoS • PPPoE – Service Name Tag, request certain DS or Service. • Allows CAC • Integrate with/similar to SBM? • One session/service or DSCP • PPP – DiffServ SLA negotiation • Allows CAC – Fragmentation (slow link) 25/10/2000 QoS in PPPoE 13
QoS • QoS scope 25/10/2000 QoS in PPPoE 14
QoS • Mapping DS to 802.1p – Static – Hint in DS field – SBM • Recommendation: Ethernet Traffic Class Service Class 7 Network Control Guaranteed Service – Static 6 Voice Low Delay (-jitter) 5 Video – Proposed mapping 4 Controlled Load Low Loss 3 Excellent Effort – No change to PPP/PPPoE 0 Best Effort Best Effort 1 Background 25/10/2000 QoS in PPPoE 15
Multiplexing QoS • Alternatives – One PPPoE session/NSP – One PPPoE session/DS class – One PPP session/DS class 25/10/2000 QoS in PPPoE 16
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 17
Stability and Performance of PPPoE • Stability – Loss – Delay – Reorder – Duplication • Performance – Connection delay – Maximum throughput 25/10/2000 QoS in PPPoE 18
Stability • Lab 25/10/2000 QoS in PPPoE 19
Stability • Result – PADS, PAP Authentication sensitive to loss – Old LCP, IPCP packet Ids not ignored – TCP segment size smaller than necessary – Termination and Link maintenance – Delays < 3s 25/10/2000 QoS in PPPoE 20
Performance • Lab – 10Mbps FD – 1Mbps HD – 9 Mbps Load w/wo VLAN – Connection Delay 25/10/2000 QoS in PPPoE 21
1000 900 Performance 800 700 Throughput [kbps] 600 500 Serie1 400 • Results 300 200 – No significant 100 difference 0 1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 Time [s] – Except on 1Mbps HD Throughput [kbps] (variance) IP PPPoE Difference 7955 (208) 7520 (242) -5.5% 10Mbps Full-Duplex 853 (60.0) 767 (170) -10.1% 1Mbps Bottleneck – Connection 4760 (12.3) 4644 (14.4) -2.4% 9 Mbps Load 4759 (18.3) 4646 (16.1) -2.4% 9 Mbps Load VLAN sep. Delay ~7s – Can be optimised to ~1s 25/10/2000 QoS in PPPoE 22
Outline • Introduction – Quality of Service – Point-to-Point Protocol over Ethernet • Background and Model • Problem Definition • QoS in the PPPoE-based Broadband IP Access. • Stability and Performance of PPPoE • Summary, Questions & Credits 25/10/2000 QoS in PPPoE 23
Summary • QoS can be incorporated in the PPPoE architecture without changes to protocol standards. • PPPoE implementation to set Ethernet user priorities according to IP DS. • Simple multiplexing should be used, one PPPoE session/NSP. • PPP/PPPoE is reasonably stable and performs well. Some issues to be further investigated and improved. 25/10/2000 QoS in PPPoE 24
Opposition • ... 25/10/2000 QoS in PPPoE 25
Questions • ? 25/10/2000 QoS in PPPoE 26
Thank you! • Tack till Fredrik Roos, Stefan Sandell • Alla på Bredbandsnät, Telia Research AB • Tack till Björn Pehrson och Mikael Lind • Tack till alla som kom. 25/10/2000 QoS in PPPoE 27
Information • http://www.e.kth.se/~e95_pla/exjobb • Still have my opposition to do. • I am currently working at Nortel Networks’ Routing Architecture Lab: patrik.lahti@nortelnetworks.com 25/10/2000 QoS in PPPoE 28
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