IPV6, speed, broadcast, quantity devices.

[bishop]

Hello! I want to try IPV6 for nrf51822. I have a few questions:

1. How many connections can be provided by the one device?
2. Can we broadcast messages between devices?
3. What speed can be on sending/receiving messages (also speed of broadcasting)?

Thanks.

[Hung Bui]

Hi Bishop,

Please be aware that IPV6 on nRF51822 is the IPV6 over Bluetooth Smart. So it has the limitation of Bluetooth Smart on the connection between the gateway and the end node. Regarding your questions:

1. Which on device you are talking about ? The end node can connect to only one gateway at a time. It can talk to other devices over the Internet, but via the Bluetooth Smart connection with the gateway.

2. You can broadcast data between device in-range (~10m) but it's not IPV6, just normal advertising data.

3. The speed/throughput is the same as Bluetooth Smart, 128kbps in theory. When broadcasting, it's 12.4kbps by theory.

[Hung Bui]

@bishop: How many device can connect to a gateway is depend on the capablity of the gateway bluetooth chip. Currently we use off-the-self bluetooth dongle on a Raspberry PI to demonstrate as the gateway. And it is limited by the bluetooth dongle, I believe it should be no more than 8 devices at the same time. You would need to check with the Bluetooth dongle's vendors.

Please be noted that our IoT SDK is not focused on the gateway side but on the node side. Currently, it's not implemented any example that allow the node to discover other nodes in the subnet. How it's done in the SDK now is to allow a node to talk directly to other nodes using the IPV6 addresses.

But I don't think it's too hard to implement something running on the gateway to provide the list of local nodes when requested by a node.