[Tinyos-devel] AM ID guidelines for net2 protocols and other applications

[Matt Welsh]

That makes a lot more sense to me than just "protocols developed by  
net2". As Om said you only need about 15-20 IDs, but you're proposing  
to claim 128. Seems like a mismatch.

Here's a proposal. As TinyOS matures it's clear that we need some way  
to resolve AM ID space conflicts. One approach is for net2 (or some  
appropriate working group) to maintain the AM ID registry for all  
*standard* protocols included in the TinyOS core tree (apart from  
contrib). When a protocol is pushed into the main tree, it is assigned  
AM ID(s) by the net2 WG and these are published somewhere (doc wiki  
seems like a good idea). Those IDs would be assigned in the range  
128-255. The range 0-127 is marked as "unassigned" and applications  
are free to use anything in that range (at their own peril).

The main challenge with this approach is determining what constitutes  
an "official" protocol that warrants an ID in the reserved space. Over  
time I would expect accretion of "dead" protocols that are claiming AM  
IDs. One policy would be for the AM ID to have a renewal period of,  
say, 2 years. This problem would largely go away if we could move to  
16-bit AM IDs.

Matt

On Apr 29, 2008, at 10:59 PM, Philip Levis wrote:
>
> On Apr 29, 2008, at 7:41 PM, Matt Welsh wrote:
>> This seems like an unnecessarily large swath of the AM address space
>> for one small working group. It would be better to justify this in
>> terms of your actual needs, rather than projected. How many AM IDs do
>> the net2 protocols currently need and can we estimate the growth in
>> the protocol space over the next few years based on past trends?
>
> The idea was that since net2 is technically responsible for  
> protocols sitting on top of AM, it's the WG responsible for  
> preventing confusion and collisions in the AM identifier space. So  
> really, the way to see this is "protocols in the TinyOS tree use  
> this range."
>
> Phil