11

Application 2: Automatic private line bandwidth

modification

Outline Private line view vs. IP view "Vertical" vs. "horizontal" triggers of SPC/SC

setup/release CHEETAH testbed and software Prototype automatic PL bandwidth

modification application

Malathi VeeraraghavanUniversity of Virginiamvee@virginia.edu

Nov. 20, 2007

Presentation for Sycamore Networks

2

Control plane

Key differentiator for SN16000 Control plane

What type of network service is enabled by control-plane software? Dynamic circuit service (DCS)

What is missing: Applications that will trigger dynamic circuit

service

3

Type of services offered today

Private line (PL) or leased line services Business interconnect Internet access

IP service

Private line (PL) IP

4

Introduction of DCS

How can DCS be introduced within the existing context of PL and IP services? PL bandwidth modification Dynamic CDN

Application 1 discussed in previous set of slides

Private line IPDynamic circuit services (DCS)

5

PL bandwidth modification

Carrier approach (using Verizon example) Provide business customer web portal

access to manually request increase or decrease of PL bandwidth

Basis for this approach: PL bandwidth modification is only required

when aggregate traffic needs change

6

Current ITU-T approach: "vertical"

NMS triggers SPC setup, modify, release Verizon's web portal likely

communicates with NMS

Figure I 5/G.7718/Y.1709 Hybrid intra-carrier network for SPCs (simple case)

Draft new Recommendation G.7718/Y.1709 (for consent)

7

Key point

Need for increased speed of PL: Single file transfer Instead of only when aggregate traffic increases

Our recommendation: "Horizontal" approach

trigger SPC setup from end host file-transfer applications

Provide software in servers located at business to allow an enterprise user to request additional bandwidth on a PL for a single high-speed file transfer

8

Horizontal approach: SPC/SC setup trigger from end-host application, e.g. storage

Private line leased between business locations: OC3c-2v (300Mbps)

Router interface cards: 1GiGE Rate limiting enforced on SN16000 GiGE ports

Business interconnect PL (300 Mbps)

Private line (PL) carriermetro ringor metro mesh network

1GigE

Enterprise

IP router

Host

Enterprise

Storageserver

1GigE

1GigE1GigE

IP router

9

1

Horizontal thinking: SPC setup trigger from user application, e.g. storage

Dynamically increase PL rate to 1Gbps Decreases file transfer delay Assumes PL is the bottleneck link

Business interconnect PL (300 Mbps)

Private line (PL) carriermetro ringor metro mesh network

1GigE

Enterprise

IP router

Enterprise

Storageserver

1GigE

1GigE1GigE

IP router

Storageclient

DCSclient

Host

DCSserver

1

2

DCSserver

34

10

Steps in previous slide 1: When storage client starts a backup, the DCS client

sends a message to DCS server 2: DCS server communicates via EMS or directly to

SN16000 to set up additional OC3c's, increase rate limit on GiGE port, and thus increase end-to-end bottleneck link rate to 1Gb/s

3: For scalability, deploy one DCS server per SN16000; signal egress SN16000 about increase

4: sets rate limit on GigE port 5: (not shown in figure) When files are transferred,

storage client through the signaling client can have the DCS server initiate release of additional OC3c's and decrease rate limit to 300Mbps

11

UNI-C support in routers

Currently only high-end routers such as Cisco's CRS-1 and 12008XR router supports UNI-C

Business routers are not likely to be these high-end routers

Alternative solution feasible if UNI-C is to used to invoke additional OC3c circuit setup Have DCS server deployed per IP router

12

G.7718 states

"The CP-MP interface shall support ... The ability to invoke the setup of a SPC The ability to invoke the release of a SPC The ability to invoke the modify operation of a SPC ... Notifications of the setup, release and modifications

of SCs" Private line type view Notifying MP of SPC/SCs will be too expensive

if SPC/SCs are short-held

13

PL view vs. IP view

The ITU-T approach: "PL view" Views the provisioning of SPCs and SCs as

comparable to "private line" Durations: Long-held

"IP view" While an IP router keeps count of the number

of packets in and out of its interfaces, it does not "notify" the management plane about every packet that arrives on its interfaces

Apply this view to SPC or SC setups/releases invoked by "horizontal" host applications

14

Two "new" concepts

Increase speed for single file transfers Rather than only when aggregate demand

increases Invoke SPC/SC setup/release from end

host applications rather than from NMS

15

File transfer delay

File transfer delay is determined by bottleneck link rate, r = min(r1, r2, r3, r4, r5)

packet loss rate on end-to-end path, Ploss

round-trip time (RTT) On lightly loaded paths, RTT and Ploss do not

matter for large files Only bottleneck link rate, r, matters

r1 r5

r4

r3r2

16

Throughput - approximate formula

Throughput is effective rate, reffective

Parameters r: Bottleneck link rate RTT: Round-Trip Time MSS: Maximum Segment Size p: Packet loss on the path

The macroscopic behavior of the TCP congestion avoidance algorithm by Mathis, Semke, Mahdavi & Ott in Computer Communication Review, 27(3), July 1997

)1

,min(pRTT

MSSrreffective

17

TCP/IP file-transfer delays

In heavily loaded paths, e.g., if Ploss = 1% RTT = 50ms

effective transfer rate 1.8Mbps if r is more than this value, it does not determine

effective rate. Ploss and RTT are main factors. if increasing r causes Ploss to decrease, effective

rate can be improved. Metro area, e.g.

RTT = 1ms, Ploss = 1% effective transfer rate 75Mbps

18

File-transfer delay (approximation)

For large files: File-transfer delay: D (sec) File size: S (bits) Throughput: reffective (b/s)

effectiverS

D

1919

Outline check

Outline Private line view vs. IP view "Vertical" vs. "horizontal" triggers of

SPC/SC setup/release CHEETAH testbed and software Prototype automatic PL bandwidth

modification application

20

CHEETAH concept

NIC 1

NIC 2

RSVP-TE client Application

TCP/IP

C-TCP/IP

End Host

NIC 1

NIC 2

RSVP-TE clientApplication

TCP/IP

C-TCP/IP

End Host Internet

SONET circuit-

switched network

SN16000 SN16000

Circuit-TCP: TCP minus congestion control; use if circuit is host-to-host.

Use high-speed circuit for file transfer applicationsCircuits: GigE VLAN mapped to OC3cNv circuit mapped to GigE VLANNIC1 and NIC2: GigE network interface cardsSN16000 links to Internet: Ethernet management portsIPsec tunnels used on Internet control-plane

CHEETAH implementation

21

Signaling and routing

RSVP-TE client developed for end hosts (Linux PCs) sends RSVP-TE messages to Sycamore SN16000.

Built-in controller of SN16000 used for dynamic call setup and release

OSPF-TE used between SN16000 switches Solution works with 7.6.2.1 release of

SN16000 software: GbE mapped to OC3-7v

Extending for VLANs and sub-Gbps rates

22

CHEETAH end-host software

End Host

bwlib Sig_proc

CAC

Data-planeConfiguration

RSVPD

RSVP-TE messages

Configuration file

read

circuitrequestor

Parsing/Construction

RSVP-TE client software architecture

Connection Admission Control:check if bandwidth is availableon the UNI from the host to the switch (multiple VLANs)

Configure IP routing and ARP table since remote host is reached directly on the newly setup circuit

2323

CHEETAH testbed

Atlanta

SN16000

ORNL, TN

OC192

Zelda1/2/3

3xGbE

GbE

Zelda4/5

Wukong/Wuneng

OC192

Raleigh, NC

SN16000

SN16000

•Long-distance OC192s purchased from NLR and ORNL•Collocation services purchased from MCNC in NC, SLR in Atlanta•Zeldas and wukong/wuneng: Linux Dell PCs

2424

Outline check

Outline Private line view vs. IP view "Vertical" vs. "horizontal" triggers of

SPC/SC setup/release CHEETAH testbed and software Prototype "automatic PL bandwidth

modification" application for storage

25

New implementation required

DCS server DCS client Shell script to wrap storage (or other suitable

business file-transfer application) with DCS client Business end user "unaware" that application is

requesting bandwidth increase prior to file transfer EMS software to obtain RSVP-TE logs on

dynamic circuit setup/release for usage-based billing support

26

Summary Opportunity to leverage SN16000's strength in control

plane implementation While control-plane allows carriers to offer Dynamic Circuit

Service (DCS), without applications, the service is not likely to be used by business customers

Applications identified for DCS: Dynamic CDN Automatic PL bandwidth modification

CHEETAH SN16000 based testbed available for testing applications

Looking for support: Student HR support to implement applications for dynamic

circuit services Cheetah testbed annual maintenance charges