Hash Key Type 15: 3-Tuple GTPv0 Sorted

Napatech Link-Capture™ Software Features

Platform
Intel® PAC
Napatech SmartNIC
Content Type
Feature Description
Capture Software Version
Link™ Capture Software 12.9

Hash key data

Hash key type 15 is a 3-tuple where the hash key data is the contents of these packet header fields:

  • 32-bit IPv4 / 128-bit IPv6 source address
  • 32-bit IPv4 / 128-bit IPv6 destination address
  • 16-bit GTPv0 flow label

For hash key type 15, the source and destination IP addresses are XORed together. The XORed value is stored in hash key data word 0 / 0 – 3 whereas 4 / 4 – 7 are zeroed. This means that frames sent from IP address A to IP address B will generate the same hash value as frames sent from IP address B to IP address A.

The GTPv0 flow label is always placed in the lower 16 bits of hash key data word 8. The rest of this word is all zeros.

For IPv4 packets, hash key data words 1 – 3, 5 – 7 and 9 are all zeros for hash key type 15. For IPv6 packets, hash key data word 9 is all zeros for hash key type 15.

Validity

Hash key type 15 is valid for frames containing an IPv4 packet or an IPv6 packet with a GTPv0 packet as payload.