I just finished integrating OCS R2 with a Cisco CallManager deployment. Everything was working as expected (this was an upgrade from R1).
But because this was R2, I was eager to test out the new OCS dial-in conferencing service. So I provisioned myself a bridge number and PIN and dialed in using a Cisco 7941 IP phone. And that’s when I met the conferencing lady… and my troubles began.
Relationship Woes
The conferencing lady answered & prompted me for the conference ID. I entered my Bridge 12345. But to my great dismay, she promptly rejected me!! "Sorry I can’t find a conference with that number". Hmm… She didn’t really sound all that sorry… I tried again, pushing the buttons more slowly, thinking maybe this attendant wasn’t the sharpest gal around. Nope. "Sorry I can’t find a conference with that number". This time, I’m pretty sure I detected a mocking tone in her voice. I tried one more time, zipping the numbers in as fast as I could. And it worked! (?) No patience for slow people, I guess. OK, fine.
Then I cautiously entered my extension to authenticate, hoping not to offend the conferencing lady. That worked fine. Finally, she prompted me for my PIN. "Please enter your PIN, and then press #". Well, I got a little ahead of myself and didn’t wait for her to finish. Once I heard "Please enter your…" I tried to enter my PIN. But she kept talking, totally ignoring me, like I wasn’t there. She didn’t want to be interrupted. I’ve had bad first dates before, and this was ranking right up there. I gave it another try, and this time waited til she was done, then put in my PIN – slowly. Failure! (I forgot she’s got zippo patience.) I gave it one last try, typing in my PIN quickly – and I was in. But I wasn’t really sure I could hold up to her exacting standards every time we interacted.
OK – so this is actually a nightmare scenario: "Welcome, users, to the new conferencing system. The new conferencing lady doesn’t like when you enter digits slowly and she hates to be interrupted." There was no way I was going to roll this out to end users; they’d last about 5 seconds before dumping her.
I couldn’t just leave things the way they were: I needed to find some resolution.
The Plot Thickens
The next day I started doing some testing from cell phones and external lines. And, amazingly, the conference lady was totally different. She didn’t care how long I took to enter my digits. She didn’t care if I interrupted her, possibly even a hint of reticence in her tone now. It was as if our first date never happened! I was so relieved. Just a rocky start, and I was sure things would progress along nicely from here on out.
My mood quickly soured, however, as soon as I tried again from a Cisco IP phone. She was back to her old antics: would frequently ignore digits I entered, wouldn’t let me enter a PIN. Just as I readied the "it’s not you it’s me" speech… it hit me: I’m sending the wrong signals!
Together At Last
It had to be the DTMF that the Cisco Phones were sending. If everything worked find from cell/outside lines, but not with the IP phones… that had to be it.
I’m not going to get into the wonders of DTMF – you can read RFC 2833 etc. for that – but suffice to say there are a few different ways that phones can handle touch-tones. And it was looking like we had a mismatch here.
I went into the config for my 7941 and disabled RFC2833 DTMF tones:
and restarted the phone.
That was it: I was sending mixed (DTMF) signals. With that resolved, I could enter PINs / Conference IDs at any speed, and interrupt at any time. This was gonna work – the conferencing lady and I have been best of friends ever since.
Who knew that conferencing could have all the same intrigue and plot twists of a Jane Austen novel?
