How to Optimize The Performance of Your Computer Network

In this article, we are going to look at different rationale for optimizing networks.

Latency Sensitivity Application

• Certain real time services are more sensitive to latency.
• Streaming data packets
• VOIP, video, RDP
• Methods for optimizing the network to help with latency sensitivity.

High Bandwidth Applications

Applications that generate a lot of network traffic.  Not latency sensitive, but use a lot of resources.  These include:

• Video/music streaming
• File streaming
• Cloud applications
  • When people try to use cloud applications they are using remote resources, so that requires networks
• Want to track down the sources of high bandwidth uses.

Quality of Service

• Ensures priority of latency sensitive packets
• Built into network devices

Traffic Shaping

• Can delay less important traffic
• Makes the most of available bandwidth by throttling certain data streams
• May be on the user end or the ISP end.

Load Balancing

• Load balancing distributes workload across multiple devices.
• The user experience must be as transparent as possible.
• Load balancing methodology: 
  • Round robin between servers
    • May not be the best solutions in situation where requests vary in the amount of work they require
  • Least connections
    • Use the server that is least busy.
  • Fastest response
    • Use the server with the fastest response time.
  • Weighted round robin
    • Devices are weighted based on operational capacity

Uptime

Important statistic to administrators.  An IT infrastructure doesn’t live in a bubble, it is there to server end users, so we need to make sure we have a large up time.

• Percentage of time services are available
  • Needs vary
  • Check SLA
    • Standard Lease Agreement guarantees a level of uptime 
• May include several computers
  • Redundancy
    • Want to minimize single points of failure
  • Power back up
  • Secondary Internet
  • Backup sites

High Availability

Translates into a high uptime.   Uses a 24 hour, 365 day calendar to calculate:

90% uptime equals  36.5 Days  of downtime/year ==>  16.8 hours/week

99%  uptime equals 3.6 Days of downtime/year ==> 5.04 hours/week

99.9% uptime equals 8.76 hours of downtime/year ==> 10.1 minutes/week

Caching Engines

Devices/software that allow network to save frequently used resources to provide rapid access.  These include:

• Load Balancers
• Proxy Servers
  • Can act as a cache for certain websites
• Local Cache
  • Computers have a local DNS cache to save time.
  • Need to consider refresh time of caching with regards to resource refreshing.

Improves connection speed and reduces strain as there is less distance needed to service a request.

Fault Tolerance

• Having fail over devices available if something goes off line
• May be less robust than primary device, but maintains network connections
• Preferably automatic
  • Routers, switches, cables
  • UPS, Data back ups, cold/hot sites
  • Configure them to send warning when failover kick in
  • Need to make sure failover devices work
  • Have scheduled outages to make sure backups work

CARP

• Common Access Redundancy Protocol.
• Allows multiple host share IP.
• Transparent fault tolerance.
• Each device has shared IP address and private IP address for management.
• Can be failover or load balanced.
• Need to make sure failover devices work.
• Have to have a fake outages to make sure system works.