Network Protocol Overhead

Here are some packet overhead numbers for a few popular protocols to help with doing bandwidth requirement calculations.  This may be another add-as-we-go post, so please comment with additions or corrections.

Ethernet : 20 bytes
Frame Relay : 4 – 6 bytes
PPP : 6 bytes
MLPPP: 10 bytes
MPLS : 4 bytes

IP : 20 bytes

TCP : 20+ bytes
UDP : 8 bytes
GRE:  4 – 20+ bytes

IPSec : 50 – 57 bytes
ESP : 20+ bytes
AH : 16+ bytes
L2TP : 24 bytes
RTP : 12 bytes

Bonus:  A voice packet is always 40 bytes + data link since it will always (?) use RTP + UDP + IP.

Sources

CCNA Voice Official Exam Certification Guide (640-460 IIUC)

Protocol Overhead

Generic Routing Encapsulation

IPSec

IP Authentication Header

Encapsulating Security Payload

Aaron Conaway

I shake my head around sometimes and see what falls out. That's what lands on these pages. If you have any questions, the best way to contact me is through Twitter at @aconaway.

More Posts

Follow Me:
Twitter

3 comments for “Network Protocol Overhead

  1. January 10, 2011 at 6:58 pm

    Here is a page I always reference for overhead… Has some info on POS and ATM
    http://sd.wareonearth.com/~phil/net/overhead/

  2. Tony Brown
    January 18, 2011 at 3:46 pm

    MLPPP: 10 bytes

  3. Anton
    August 17, 2016 at 12:59 am

    Good stuffff!
    Short and to the point without all the blah blah blah!
    Tag for Google: How to calculate packet overhead vpn ipsec l2tp tcp udp mtu

    Thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *