# 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.

![](https://1093869420-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSVTipbFtaGFi2aZlOpxC%2Fuploads%2FnEUibr8YXd0Zw2J0RXGu%2F02.jpg?alt=media\&token=1e78f546-eadd-4333-89c8-b684501a7197)

#### **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.

![](https://1093869420-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSVTipbFtaGFi2aZlOpxC%2Fuploads%2Fx4mlrY4PaLYUfo2MR2l8%2F03%20copy.jpg?alt=media\&token=a03b94fa-6684-4239-9569-3813511244c3)

#### **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.

![](https://1093869420-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSVTipbFtaGFi2aZlOpxC%2Fuploads%2FvaDN8mL9RQX8x5vfvM5q%2F04.jpg?alt=media\&token=75f6625d-2bd8-4675-9120-a74a4fbdcbc6)

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.