SX20 resume issue

[hashimoto.kotaro]

Hi all,

SX20 does not display video after resuming a call with Polycom Real Presence Desktop(RPD) for Windows.

Is this a known issue?

1. Dial IP address of RPD from SX20 on H323.

2. Press HOLD button on SX20(using Cisco Touch).

3. Press RESUME button on SX20(using Cisco Touch).

=>RPD can display video from SX20, but SX20 does not display video from RPD.

Best Regards,

Kotaro Hashimoto

[Patrick Pettit]

Hi Kotaro - Yeah, its quite interesting.  It happens to my SX20, EX60 and my old school MXP it seems.  Sniffer from the desktop shows me after the empty capset for hold, and full capset for resume, the Real Presense sent OLC for audio and video and rejected cause MasterSlave Determination wasn't negotiated yet AFTER the resume.

Will do some more tests and let you know whats up. 

VR

Patrick

[hashimoto.kotaro]

Hi Patrick,

Is there any progress about this?

Best Regards,

Kotaro Hashimoto

[Patrick Pettit · Accepted solution]

HI Kotaro.  Sorry it took so long on this.  Wanted to try some different versions on this.  Went back to TC5.1.8 on EX60, and still saw the same behavior. 

You may want to approach Polycom on this.  Reason being is when the call is held/resumed by EX60, or SX20 in your case, MasterSlaveDetermination should be renegotiated AFTER the resume.  What I'm seeing in the packet trace from RPD is that AFTER the resume, it wants to open LC PRIOR to MSD.  MSD should also occur on the resume.  EX rejects the OLC for audio and video in this case. 

This is something you may want to take up with Polycom to investigate if possible. 

VR

Patrick

[hashimoto.kotaro]

Hi Patrick,

Thank you for your information

I sent an e-mail to Polycom partner to investigate this just now.

I will update this discussion if there is some answer from them.

Best Regards,

Kotaro Hashimoto

[Martin Koch]

Kotaro: just out of curiosity, how does it behave if you initiate the call via sip (I assume a VCS is in place?)

[hashimoto.kotaro]

Hi Martin,

As you expected, this issue does not happen on SIP.

(In this test we have no gatekeeper or SIP registrar)

We can hold and resume a call without any problem.

Best Regards,

Kotaro Hashimoto

[Martin Koch]

ok.thx

If its possible I would try to place both in the same Layer2 subnet so you can rule out that there

is no other layer3 (firewall/inspection/nat/alg/...) magic done.

As Patrick said, could be worth to check with the polycom support.

Please remember to rate helpful responses and identify helpful or correct answers.

[hashimoto.kotaro]

Hi Patrick, Martin,

I've got a response from Polycom partner.

They say that if SX20 implements HOLD/RESUME function using H.450.4, then HOLD/RESUME funcion does not work well.

Because Polycom Real Presence does not correspond to H.450.4.

https://www.itu.int/rec/dologin_pub.asp?lang=e&id=T-REC-H.450.4-199905-S!!PDF-E&type=items

Best Regards,

Kotaro Hashimoto