Null - Ping and Padding Layer (00h)
OSI: Transport Layer
Keywords: keep-alive, padding in framing, encapsulation, low communication overhead, sensors, internet of things, embedded systems, sensor networks
Scope
The scope of this project is to define the Isotropic Sensor Network User layers for broadcast and peer to peer connection in distributed sensor area network, wired or wireless, low and high data rate devices, battery powered devices, short-range devices with short operational space, low-cost devices to support trivial sensors, besides the fully featured devices.
Purpose
The purpose of this specifications is to provide a standard for low complexity, low cost, and low power (aware) consumption devices (sensors) to provide keep alive capability and padding for frame and packet alignment.
Definitions, Acronyms and Abbreviations
Packet Format
Fields |
Protocol ID |
Bits |
8 |
Value |
00h |
- Protocol ID:
defines the unique protocol identification number of the application protocol specific format
Keep alive
In many cases the underlying media cannot provide information whether a device is alive or not, or looking from a device side, whether host (peer) is connected or does it exist.
The device and host should thus support keep-alive capability in which, after reception of the packet with Null protocol only, then the queried device should respond either with some valid message or Null.
Padding
Some devices may due to internal optimization require padding bytes to align data structure to i.e. 32-bit boundaries. And in other cases packets may need to be filled to account a fixed size. In such cases the Null is used as a padding byte.
Document Changes
Date |
Release |
Changes |
September 15, 2018 |
1.0 |
Initial Specifications |