Hello,

On 8/22/12 12:18 PM, Juha Heinanen wrote:

daniel,

you wrote:

This feature should be useful in mobile networks, to avoid stacking lot of invalid contacts which could result in lot of branches causing many retransmissions.

why would a sip ua that runs in a mobile network device be configured to use udp instead of tcp?

poor battery life seems to be a big problem in so called smart phones. wouldn't this kind of active pinging make it even worse?

yes, pinging could make it worse. Personally I recommend TLS for mobile networks, to protect privacy of instant messaging, specially if there is going to be usage over public wi-fi spots. That also adds more processing to encrypt/decrypt, but it is the price of better security.

However, there are lot of sip softphones apps that still do only udp, in many cases resulting in lots of contacts in location table. Here can help also the option of saving one contact per user (via parameter of save() function), if it is known that the user should have only one device.

All over, the new functionality is optional and off by default. It is the decision of admin to enable or not, for mobile or fixed networks.

Cheers, Daniel