Alan Bodnar

October 23, 2005

MSIT 526  Fall 2005

Dr. Rebman

I.     Business Problem

A.     Global Applications

1.      Leveraged Expense applications

2.      Leveraged CRM applications         

3.      Leveraged Procurement applications

B.     Internet Applications

1.      Transaction processing

2.      Organizations web-presence and forms

C.     Network Response Time and Performance Critical

1.      Employee Confidence in IT

2.      Employee Productivity

3.      Company’s Profitability

D.     Global Infrastructure Model Exceeds TCP Protocol limitations

1.      TCP created when bandwidth was a scarce resource

2.      Bandwidth today plentiful

3.      Throughput limited by TCP protocol not bandwidth

II.   TCP Protocol Operation

A.     TCP Connection Establishment

1.      Synchronization

2.      Acknowledgements

3.      Finish

4.      Maximum Segment Size

B.     TCP Data Transfer

1.      Push Data

2.      Interactive Data

3.      Bulk Data

III.TCP Protocol Limitations

A.     Window Size

1.      Example on low bandwidth link

2.      Example on high bandwidth link

B.     Bandwidth Delay Product

1.      Measure Actual Throughput

2.      Illustration Bandwidth Delay Product low bandwidth

3.      Illustration Bandwidth Delay product high bandwidth

a)      Long Fat Pipe or Long Fat Networks

C.     Affected Platforms

1.      Windows

2.      Unix

3.      Linux

D.     Application Implications

1.      Retransmission

2.      Slow Application Response

3.      Browser Timeouts

4.      Network Meltdown

IV.              TCP Throughput Solution

A.     Business needs to exploit bandwidth capacity

B.     Business needs to avoid unnecessary traffic

C.     Window Scale Option

1.      Default Window Size

a)      16 bit

b)      65536 bytes

2.      Window Scale Option

a)      32bit

b)      1 gig

D.     Timestamp Option

E.     Protection Against Wrapped Sequence Numbers

V.  Critical to understand data flows

A.     Perform Bandwidth Delay Product Calculations      

1.      Set expectations

B.     Profile Application

1.      Understand Application Turns

2.      Understand TCP Turns

3.      Understand  Segment Size

C.     Tools

1.      Compuware

2.      Concord

3.      Spirent

VI.              Better Business Decisions

A.     IT infrastructure changing

B.     Application deployments changing

C.     Need for accurate infrastructure and application information essential

1.      Limited resources

a)      Financial

b)      Labor

2.      Spend it in the right place