Re: [sipcore] About SUBSCRIBE method's performance and Out-of-Dialog notification suggestion:

[Christer Holmberg <[e-mail]>]

Hi Gao, 

>By our equipment's performance analysis, we(internal) find that SUBSCRIBE method always occupy a lot of resource, especially for some long duration Event Packages. (Considering the traffic 
>model, some Event Packages, have larger call rate and longer duration than INVITE method.) 
>	
>Supposing the SUBSCRIBE's dialog&event resource consuming is similar to INVITE's dialog&session(signalling level) resource consuming, one Event Package's would need more resource consuming than 
>the session usage. 
>	
>Considering some Event Package's event occurence probability is very low in the subscription's relative long duration lifecycle, we can make a new type of subscription which would tear down the 
>dialog after the SUBSCRIBE(and the first NOTIFY), while send the subsequent notification out-of-dialog. 
>	
>I'd like to hear Adam and other RFC3265 experts' view points. 

I'm neither, but I have some questions for clarifications:

1. I assume the SUB sender would still need store some data, in order to match the out-of-dialog NOT to the previous SUB dialog?

2. If 1 is true, for how long would the SUB sender keep this data, and be prepared to receive the out-of-dialog NOT? I guess the subscription timers don't apply in this case, or?

3. Would the out-of-dialog NOT be routed using a Contact/GRUU, rather than the AOR, of the SUB sender, to ensure it reaches the SUB sender?

Regards,

Christer