slide1 l.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
VPNs PowerPoint Presentation
Download Presentation
VPNs

Loading in 2 Seconds...

play fullscreen
1 / 12

VPNs - PowerPoint PPT Presentation


  • 332 Views
  • Uploaded on

VPNs Virtual Private Networks Use the Internet for transmission instead of a PSDN Sometimes called VPNs if use Frame Relay or ATM with added security Internet VPNs Why use the Internet? Inexpensive Business partners are already connected to the same network (the Internet)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'VPNs' - ostinmannual


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1
VPNs
  • Virtual Private Networks
    • Use the Internet for transmission instead of a PSDN
    • Sometimes called VPNs if use Frame Relay or ATM with added security

Internet

slide2
VPNs
  • Why use the Internet?
    • Inexpensive
    • Business partners are already connected to the same network (the Internet)
      • May use different PSDNs, but everybody is connected to the Internet
slide3
VPNs
  • Problems with the Internet
    • Congestion: slows transmissions
    • Reliability: cannot always connect, sometimes fails during transmissions
    • Lack of security
slide4
VPNs
  • IETF developing IPsec security standards
    • IP security
    • At the internet layer
    • Protects all messages at the transport and application layers

E-Mail, WWW, Database, etc.

TCP

UDP

IPsec

slide5
VPNs
  • IPsec Transport Mode
    • End-to-end security for hosts

Local

Network

Internet

Local

Network

Secure Communication

slide6
VPNs
  • IPsec Tunnel Mode
    • IPsec server at each site
    • Secure communication between sites

Local

Network

Internet

Local

Network

IPsec

Server

Secure Communication

slide7
VPNs
  • IPsec Modes Can be Combined
    • End-to-end transport mode connection
    • Within site-to-site tunnel connection

Local

Network

Internet

Local

Network

Tunnel Mode

Transport Mode

slide8
VPNs
  • Another Security System for VPNs is the Point-to-Point Tunneling Protocol (PPTP)
    • For dial-up connections, based on PPP
    • Connects user with securely to a remote access server at a site

Dial-Up

Connection

Local

Network

Internet

PPTP Connection

Remote Access Server

virtual private networks
Virtual Private Networks
  • Other Problems Remain
  • Internet Congestion is Still a Problem
    • Internet throughput tends to be low
  • Internet Reliability is Low
    • Cannot get connections
    • Backbone fails occasionally
virtual private networks10
Virtual Private Networks
  • Alternative
    • Avoid the congested and unreliable backbone!
    • Use one ISP that serves all sites
    • Should offer QoS service level agreement (SLAs) for latency and reliability

Site 1

ISP

Site 2

virtual private networks11
Virtual Private Networks
  • Alternative
    • Avoid the congested backbone
    • Use ISPs that “peer” with one another: connect with one another not through the Internet backbone
    • May offer end-to-end SLAs

Site 1

ISP A

ISP B

Site 2

Peering

wans in perspective
WANs in Perspective
  • Both Leased Line Networks and PSDNs are widely used and will be for several years to come
  • Leased Line Networking is shrinking while PSDN networking is growing rapidly
  • VPN technology and standards are still immature and use will be very low for several years to come