S110 mtu change

RE: S110 mtu change

endnode — Tue, 18 Apr 2017 11:06:59 GMT

Yes, under some condition you can achieve higher effective bandwidth on top of GATT with non-default ATT_MTU size, however again this is very application-dependent. Don't get confused by some simulated numbers, it's important if your application is half duplex/full-duplex, what are typical packet sizes on top of (G)ATT MTU, if the protocol is completely asynchronous or if it is command-response pair etc. I'd recommend to grab few Dev Kits and simulate it, there is nothing better then proper feasibility study...

RE: S110 mtu change

zcmm — Tue, 18 Apr 2017 08:22:10 GMT

ok,why increased ATT_MTU SIZE have high througout?May be beacause Per Connection interval have 6 packet,per packet is ATT_MTU size?

RE: S110 mtu change

zcmm — Tue, 18 Apr 2017 06:52:40 GMT

thanks,can you tell which chapter?i find the MTU MAX SIZE IS 23BYTES ATT both S110 V2.0 and S130 V2.0.
changing MTU is supported for above BLEV4.1?

RE: S110 mtu change

endnode — Tue, 18 Apr 2017 06:15:37 GMT

Edit: sorry, my bad, none of nRF51 SoftDevices support ATT_MTU change procedure, all are capable of default size (23B) only. Note that using BT SIG specification version for feature list is pretty confusing, none of them demands ATT_MTU exchange procedure as mandatory features so you can have BLE stacks (like several Nordic Soft Device types/versions) which are certified as v4.1 or v4.2 but don't support that. It's similar with other features (like PDU extension), always reed detailed spec/feature list not just BT SIG version mentioned in certification documents.