Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)

LOOK UP ANOTHER TERM


layers 4-7

See layer 4-7.



layer 4-7

The two layers in a network packet that identify its content (for details about layers, see TCP/IP and OSI model). The bottom layers 1, 2 and 3 are the protocols that move a network packet from source to destination. Layers 4 and 7 identify the application that created the packets as well as the specifics of the request. For example, inspecting layer 4 can identify HTTP traffic (Web traffic), but inspecting layer 7 can determine what the HTTP request is for (see Web switch). See layer 4 switch and well-known port.



 TCP/IP SWITCHING/ROUTING DECISIONS

  Layer and      Forwarding
  Protocol       Decision
  Inspected      Based on

  2 - Ethernet   MAC address

  3 - IP         Network address
  3 - IP         Service quality

  4 - TCP/UDP    Traffic type
      socket     (HTTP, FTP, etc.)

  7 - HTTP       HTTP request type





Personal Use Only

Before/After Your Search Term
BeforeAfter
layer 4 switchlayman
layer 7laymanize
layer 7 switchlayout engine
layer of abstractionlayout setting
layer2lazer
layer3lazy loading
layer4lazy write
layer7LBA
layered architectureLBRV
layersLBS

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
Audio/VideoGraphics
MainframesSecurity
ProgrammingHealthcare IT
System design