<p dir="ltr">Mike (and anyone else who reads this):</p>
<p dir="ltr">Is there a standard for PTT on SIP, either formal or ad hoc? If not, do you know of anywhere there's a write up of an actual or a proposed implementation?</p>
<p dir="ltr">I'm interested in this functionality, too. We have a large public safety market here that makes heavy use of PTT.</p>
<p dir="ltr">Also, are you aware of any SIP capable PTT handsets? And any portables that can carry both, for example, 800 band radio and GSM?<br></p>
<p dir="ltr">Thanks,<br>
Larry Morley</p>