> For the complete documentation index, see [llms.txt](https://docs.nitro.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nitro.network/lorawan-on-nitro-network/organizationally-unique-identifier.md).

# Organizationally Unique Identifier

Each Network Server on the Nitro Network acquires an Organizationally Unique Identifier (OUI).

### **Join-request and join-accept messages**

To participate in the Nitro Network, each end-device has to be personalized and activated.

A LoRaWAN device can be defined by (AppEui, DevEui) and DevAddrs has to be allocated during the join procedure.

The join-request/accept messages are used by the over-the-air activation procedure for roaming purposes.

#### **Join-request message**

The join procedure is always initiated from the end-device by sending a join-request message.

![](/files/tbWTv6l4QTPCIAqLNwcA)

#### **Join-accept message**

The network server will respond to the join-request message with a join-accept message if the end-device is permitted to join a network.

![](/files/gPmagF99QGZYa9WnTgUS)

#### **Data Stored in the End-Device after Activation**

After activation, the following information is stored in the end-device: a device address (DevAddr), an application identifier (AppEUI), a network session key (NwkSKey), and an application session key (AppSKey).

The DevAddr identifies the end-device within the current network. 

DevAddr consists of a network identifier and network address.

![](/files/XR2ZHkkuHjXxK1vMOpir)

The network identifier (NwkID) used to separate addresses of territorially overlapping networks of different network operators and to remedy roaming issues.

The network address (NwkAddr) of the end-device, can be arbitrarily assigned by the network manager.