LORA Network Name and Network Pass Phrase.

[Tom Hill]

Based on the Link the Network Name and Pass Phrase need to be a minimum 8 chars long and is case sensitive.

1) Is there an upper limit on the network name and phrase or there any validations run on the conduit while configuring this?

2) If the passphrase is long would this be of any concern with nodes/mdots located at a larger distance from the conduit? I am just curious since the further away an mdot is from the conduit the data packet size that can be transmitted seems limited and not sure if it affects while attempting to join the network having long network passphrases.

Thanks,
Yogesh

[Mike Fiore]

Yogesh,

The mDot API documents the limits for network name and passphrase.

        /** Set network name
         * for use with OTA & AUTO_OTA network join modes
         * generates network ID (crc64 of name) automatically
         * @param name a string of of at least 8 bytes and no more than 128 bytes
         * @return MDOT_OK if success
         */
        int32_t setNetworkName(const std::string& name);

        /** Set network passphrase
         * for use with OTA & AUTO_OTA network join modes
         * generates network key (cmac of passphrase) automatically
         * @param name a string of of at least 8 bytes and no more than 128 bytes
         * @return MDOT_OK if success
         */
        int32_t setNetworkPassphrase(const std::string& passphrase);

Since the dot side limits the strings to 128 characters, it wouldn’t make sense to go any higher on the gateway.

WRT your second question, the name and phrase are turned into an EUI and KEY which are fixed length. So the same number of bytes are transmitted in your join request regardless of what the name and phrase are.

Hope this helps!

Cheers,

Mike

[Tom Hill]

Thanks Mike that was very helpful. Is it a good practice to have just a series of numbers for the network name? Is there some good practice for network names that we should be using, so there is no collisions in where multiple conduits exist in fairly near proximity? Since the network id is being generated based on the comments above.

Thanks,
Yogesh

[Mike Fiore]

Yogesh,

As long each conduit in near proximity has a different network name and passphrase from the others, you shouldn’t have any confusion among your devices. Even changing one character in the name will be enough.

Network ID = crc64(Network Name)

The chances of collision are extremely low since you probably won’t have more than a few gateways within range of each other.

Cheers,

Mike

[Jason Reiss]

http://stackoverflow.com/questions/6025445/how-likely-are-two-blocks-of-data-likely-to-produce-the-same-crc64-value

[Tom Hill]

Thanks Mike and Jason for clearing things up and taking the time to respond.

Thanks,
Yogesh

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