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.

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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!

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