On Thu, Nov 29, 2018 at 2:33 PM Alex Balashov <abalas...@evaristesys.com> wrote:
> I have a SIP registrar with a policy-based registration interval floor > of 60 seconds. > > One would expect that this means most devices would register with such > an expiry time, and then refresh the registration a few seconds before > it expires. > > However, there are numerous endpoints out there which refresh the > registration at much higher frequencies, sometimes as low as every few > seconds. That is to say, they request an interval of 60 seconds or more, > but re-register every 2-5 seconds. > Some devices do this to keep a pinhole in NAT firewall open. Pleases see if you can enable keep-alive on your proxy and the device for the same purpose (https://tools.ietf.org/html/rfc5626#section-3.5). > I am putting in a mechanism to stop this, as it generates unnecessary > load and is generally poor form. I am not sure, however, what the > appropriate SIP response to these endpoints should be. My best guess is > that '480 Temporarily Unavailable' with a 'Retry-After' header would > make the most sense, but the language in the RFC is ambiguous as to > whether this response is only contemplated in the context of a 'call' as > opposed to a registration flow. > We have successfully used 480 with "Retry-After" to reduce the load on the proxy after network connectivity disruption, so this should work for your purpose, but I would still suggest addressing the root cause. Other option is too have proxy to use some sort of in-memory DB to efficiently handle frequent registrations for devices that do no support SIP keep alive. Regards, _____________ Roman Shpount _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
