How to say that youre special: Can we use bits in the IPv4 header? - - PowerPoint PPT Presentation

How to say that you’re special: Can we use bits in the IPv4 header?

Runa Barik (UiO), Michael Welzl (UiO), Ahmed Elmokashfi (SRL) Applied Networking Research Workshop 2016 Berlin, Germany 16th July 2016

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Test methodology and Locations

ICMP packet (Echo Request) I C M P p a c k e t ( E c h

• R

e p l y ) Test Packet Test Packet id=id2 T C P S Y N , i d = i d 1 Client Server

Middlebox Router Router

id=id1 T C P S Y N / A C K , i d = i d 2

(a) Client initiated TCP SYN-SYN/ACK Handshake (b) Client Locations: Australia, Austria, Bangladesh, Germany, Norway, Spain, Sweden, Switzerland and United King- dom

Measure what middleboxes do to DSCP , ECN bits (and the Evil bit, and the Identification field)

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DSCP values 10-3 10-2 10-1 100 10 8 36 46

(0: 98),(2: 5) (6: 17) (8: 5) (46: 41) (0: 97),(2: 7) (4: 14),(8: 5) (34: 2) (36: 39) (0: 112) (2: 5) (8: 45) (0: 170) (2: 5) (8: 5) (32: 5)

Fraction of distinct paths DSCP values

2 8 32 32 32 32 2 8 2 4 8 34 34 34 34 36 36 36 36 2 6 8 46 46 46 46

x-axis: the lower (larger) number is the original DSCP value, the upper (smaller) number is the changed value. The brackets on the top show the absolute number of paths (IP address pairs).

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