# Packet Header

This packet header structure contains:

| Field Name     | Description                                                      |
| -------------- | ---------------------------------------------------------------- |
| Timestamp      | Specify a time interval (elapsed time)                           |
| Capture Length | Length of portion present (must be less then or equal to Length) |
| Length         | Length of current received packet (off wire)                     |

{% hint style="warning" %}
This header are not freed by the caller, and not guaranteed to be valid after the next call to Pcap.next(PacketHeader), Pcap.nextEx(PacketHeader, PacketBuffer), Pcap.loop(int cnt, PacketHandler, \<T>), and Pcap.dispatch(int cnt, PacketHandler, \<T>).
{% endhint %}