Hot Downloads

Welcome, Guest
Username: Password: Remember me

TOPIC: Encapsulation

Encapsulation 5 years 11 months ago #35748

  • Ophelia
  • Ophelia's Avatar
  • Offline
  • New Member
  • Posts: 5
  • Karma: 0
Hello there. I have a small question...
When passing down data on the osi layers with encapsulation which percentage of the data received of the physical layer is the actual message?

e.g Message 100byte, Ip header 20 byte, TCP header 20 byte, ethernet header 14 byte and ethernet tailer 4 byte.

It's like... Message/58byte *100% ? or there are some additional bytes?

Thanks a lot! :)
The administrator has disabled public write access.

Re: Encapsulation 5 years 10 months ago #35824

  • S0lo
  • S0lo's Avatar
  • Offline
  • Moderator
  • Posts: 1577
  • Thank you received: 7
  • Karma: 3
Infact there can be some additional data added by the physical layer for signaling or encoding. For example Manchester encoding (which is used in Ethernet) adds a preamble to allow for synchronisation, the preamble consists of 64 alternating 1s and 0s sent before the frame.

Other encodings such as the 4B/5B exist which encodes each 4bits as a 5bit pattern to provide for synchronization.
Studying CCNP...

Ammar Muqaddas
Forum Moderator
The administrator has disabled public write access.
Time to create page: 0.076 seconds


Cisco Routers

  • SSL WebVPN
  • Securing Routers
  • Policy Based Routing
  • Router on-a-Stick

VPN Security

  • Understand DMVPN
  • GRE/IPSec Configuration
  • Site-to-Site IPSec VPN
  • IPSec Modes

Cisco Help

  • VPN Client Windows 8
  • VPN Client Windows 7
  • CCP Display Problem
  • Cisco Support App.

Windows 2012

  • New Features
  • Licensing
  • Hyper-V / VDI
  • Install Hyper-V


  • File Permissions
  • Webmin
  • Groups - Users
  • Samba Setup