QoS in PPPoE - KTHe95_pla/exjobb/doc/presentation.pdf · 25/10/2000 QoS in PPPoE 2 Outline •...

QoS in PPPoE

Quality of Service in the Point-to-Point Protocol over Ethernet

Master’s Thesis

Patrik LahtiKTH, Telia Research AB

25/10/2000 QoS in PPPoE 2

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


Quality of Service

• Enhance the network with the intelligence to treat traffic according to application requirements.– Delay

– Delay variation

– Loss

– Others...

• IP– Differentiated Services

– Integrated Services

• Ethernet– Priorities (802.1p)

– Subnet Bandwidth Manager


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


PPP/PPPoE

t

Mulitcast PADI, w Service-Name

Unicast PADR, w Service-Name

Unicast PADO, w Service-Name(s)& AC-Name

Unicast PADS, w Service-Name& Session ID

Unicast PADO, w Service-Name(s)& AC-Name *)

*) There may be multiple ACs answering with a PADO**) May be sent by either side

PPP session Stage

Unicast PADT, w Session ID **)

Client AC

LCP

Auth

IPCP

IP data

ACClient


Outline









Background& Model

• CPN

• VLAN

• IP Access Node

• New Services => QoS

• NSP selection

• ProtocolsATM

STB

PC

IPT

Ethernet Sw

Ethernet Sw

Ethernet Sw

IP-accessNode

AAA

IP Network

100Mbps Ethernet

10Mbps Ethernet

1Gbps Ethernet

ADSL.

STB

PC

IPT10Mbps Ethernet

ADSL

DSL

AM

Ethernet

PPPoE

Physical

PPP

IP

Ethernet

Physical

Ethernet

Physical

Ethernet

Physical

Ethernet

Physical

Ethernet

PPPoE

Physical

PPP

IP

Sw Sw

?

IP

CustomerEquipment

EthernetSwitch

EthernetSwitch

IP-accessNode


Why PPP/PPPoE?

+ NSP selection

+ IP address allocation

+ Reuse of Legacy Equipment

+ Unified Model (Bridged ADSL)

+ Familiar to users

+ Per user access control and billing

- Overhead and Connection delay(?)

- Software update for Clients

- QoS issues unresolved (?)


Outline








25/10/2000 QoS in PPPoE 10

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 11

Outline








25/10/2000 QoS in PPPoE 12

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 13

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 14

QoS• QoS scope

25/10/2000 QoS in PPPoE 15

QoS

• Mapping DS to 802.1p– Static

– Hint in DS field

– SBM

• Recommendation:– Static

– Proposed mapping

– No change to PPP/PPPoE

Ethernet Traffic Class Service Class

7 Network Control Guaranteed Service

6 Voice Low Delay (-jitter)

5 Video

4 Controlled Load Low Loss

3 Excellent Effort

0 Best Effort Best Effort

1 Background

25/10/2000 QoS in PPPoE 16

Multiplexing QoS

• Alternatives– One PPPoE session/NSP

– One PPPoE session/DS class

– One PPP session/DS class

25/10/2000 QoS in PPPoE 17

Outline








25/10/2000 QoS in PPPoE 18

Stability and Performance of PPPoE

• Stability– Loss– Delay– Reorder– Duplication

• Performance– Connection delay– Maximum throughput

25/10/2000 QoS in PPPoE 19

Stability

• Lab

25/10/2000 QoS in PPPoE 20

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 21

Performance

• Lab– 10Mbps FD

– 1Mbps HD

– 9 Mbps Load w/wo VLAN

– Connection Delay

25/10/2000 QoS in PPPoE 22

Performance

• Results– No significant

difference

– Except on1Mbps HD

– ConnectionDelay ~7s

– Can be optimised to ~1s

0

100

200

300

400

500

600

700

800

900

1000

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65

Time [s]

Thro

ughp

ut [k

bps]

Serie1

Throughput [kbps] (variance) IP PPPoE Difference

10Mbps Full-Duplex 7955 (208) 7520 (242) -5.5%

1Mbps Bottleneck 853 (60.0) 767 (170) -10.1%

9 Mbps Load 4760 (12.3) 4644 (14.4) -2.4%

9 Mbps Load VLAN sep. 4759 (18.3) 4646 (16.1) -2.4%

25/10/2000 QoS in PPPoE 23

Outline








25/10/2000 QoS in PPPoE 24

Summary

• QoS can be incorporated in the PPPoEarchitecture without changes to protocol standards.

• PPPoE implementation to set Ethernet user priorities according to IP DS.

• Simple multiplexing should be used, one PPPoEsession/NSP.

• PPP/PPPoE is reasonably stable and performs well. Some issues to be further investigated and improved.

25/10/2000 QoS in PPPoE 25

Opposition

• ...

25/10/2000 QoS in PPPoE 26

Questions

• ?

25/10/2000 QoS in PPPoE 27

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 28

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:[email protected]

QoS in PPPoE - KTHe95_pla/exjobb/doc/presentation.pdf · 25/10/2000 QoS in PPPoE 2 Outline •...

Documents

Transcript of QoS in PPPoE - KTHe95_pla/exjobb/doc/presentation.pdf · 25/10/2000 QoS in PPPoE 2 Outline •...