topic Re: Webex Calling audio delays during call initiation in Webex Calling

Webex Calling audio delays during call initiation

Maxwell Paine — Wed, 11 Dec 2024 20:10:50 GMT

We switched from CUCM and now utilizing Webex calling. We have an issue with audio delays. When calling another person internally at the same site many times there may be a very short delay between answering the phone and being able to hear each other. The phone immediately shows as on call just missing the audio for half a second. Lots of "hello?" back and forth for a few seconds until both users can actually hear each other. Where it is very noticeable is if one party or the other is on a cell phone locally or remotely calling/answering utilizing the Webex app. This delay is sometimes 2 or 3 seconds. Call quality is fine it's just the delay. Cisco TAC was engaged and pointed to high jitter (50ish ms avg), so we rectified that, and the issue is still there. Going back to Webex Calling TAC to try and figure out what is still going on, but wondered if the community had any suggestions.

Re: Webex Calling audio delays during call initiation

williamhodgins — Fri, 03 Jan 2025 18:59:49 GMT

I was having this problem as well and Cisco TAC told me that disabling ICE might help because it can cause a delay at the beginning of a call which is documented here: Webex Calling Media Optimization with Interactive Connectivity Establishment.

They provided the following instructions to disable the setting for the location having the issue, which fixed the problem for me:

In Control Hub > Locations, select the location having the issue (if there are multiple sites, go through the steps for each site).
Under the Calling tab, scroll down to Device management section and click Manage.
Select the Define custom device settings radio button, and then MPP tab.
Scroll down to the ICE option and turn off the toggle.

Click on Review Changes and Start processing to apply the new settings.

Another thing to note is that an individual phone might still have ICE enabled on a device level, which overrides the global setting, so check that as well if you're still having an issue.

Hopefully you and anyone else having this problem finds that helpful.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Sun, 27 Apr 2025 15:12:34 GMT

I’m experiencing the same issue with our customers.
There is a 2–3 second delay for internal calls.
At the same time, customers are complaining about call transfers — they have to transfer very slowly; otherwise, the transfer fails.

Is anyone else experiencing this problem too?

i am still not sure if disable the ICE solve the problem ,i wait to the customers update

Re: Webex Calling audio delays during call initiation

koons — Thu, 08 May 2025 14:00:05 GMT

Has anyone found a resolution to this issue? I'm a colleague of Max(who originally started this post) and we still continue to have this issue. Disabling ICE actually makes it worse.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Sun, 11 May 2025 13:58:33 GMT

Dear William,

Thank you for your response.

I have already tested the impact of ICE on the RTP, but unfortunately, it didn’t help resolve the issue.
I also opened a support case, but they were unable to identify the problem.

That’s why I’d like to know if anyone else has encountered this issue.

Re: Webex Calling audio delays during call initiation

ckeuk — Wed, 18 Jun 2025 13:26:52 GMT

I would like to know if a resolution was found as well. I've been emailing TAC back and forth with no resolution. Lots of audio delay. Seems like switching over to a softphone resolved the majority of the issue but we have users who prefers good ol hard phones.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Thu, 19 Jun 2025 10:09:57 GMT

Dear All,

I also tested the impact of ICE on the RTP stream, but unfortunately, it did not work for me either. I was unable to find a solution to this issue.

Additionally, I have closed the support case, as they were unable to assist further with this problem.

Please let me know if anyone has found a workaround or has any suggestions.

Re: Webex Calling audio delays during call initiation

Michalis Papasavva — Mon, 30 Jun 2025 12:54:24 GMT

Hi,

Did you find any solution for this?

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Mon, 30 Jun 2025 17:20:26 GMT

no i think the customer get use to this delay

you have this problem also ?

Re: Webex Calling audio delays during call initiation

Michalis Papasavva — Tue, 01 Jul 2025 06:04:38 GMT

Yes, I disabled the ICE option on phones, which was help to decrease the delay, but it's still noticeable to customer.

Re: Webex Calling audio delays during call initiation

SCOTT MILLER — Fri, 10 Oct 2025 14:05:00 GMT

Hi,

I have been dealing with this exact problem with a customer (and TAC) for some time - and finally have made some progress.

Issue looks to be caused by voice packets not starting to stream until the ACK follows the 200OK, in call establishment (has been difficult to debug due to SIP TLS / encryption).

TAC can enable a per phone configuration item (not currently exposed to customer Webex orgs / customers) called "RTP_before_ACK" (default is 'No' and can be checked via cfg.xml within a Problem Report from phone web GUI) - after doing so my customer reports no 2/3 second audio delay.

So the issue does not relate to the network (having said that, I'd theorize that the issue may occur more frequently in a busier network), QoS, call recording, ICE, or STUN protocols (all of which CAN cause a slight delay in audio set up - however during my testing this was around 0.3 to 0.5 seconds - not 2 to 3 seconds).

Waiting on TAC to confirm next steps, however I would imagine they either need to make this setting enabled by default - or change the phone firmware code.

Thought I'd quickly share, as I've spent many hours looking at this problem.

Regards
Scott

**Update 04/09/25**

- TAC can set RTP_BEFORE_ACK setting at Webex Org level, or per phone (if testing).
- After this was enabled, customer reported that the problem was resolved, but it appears this may now not be the case / further occurrences of the problem have occurred
- I am continuing to work with TAC on the issue
- If anyone wants to PM me related raised TAC cases - feel free (this will help us all)

**Update 09/10/25**

- Issue looks to be with phone firmware and processing of OPUS codec
- Within devices - set Audio Codec Priority to: Primary: G722, Secondary: OPUS, Tertiary G711a
- ICE can be left enabled
- With above settings, customer no longer reports 1/2 second audio delay on internal calls

**Update 10/10/25**

- Possibly related: https://www.cisco.com/c/en/us/support/docs/field-notices/742/fn74296.html

Re: Webex Calling audio delays during call initiation

ckeuk — Thu, 07 Aug 2025 16:17:05 GMT

Keep us updated. I was asked about the issue again this morning.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Sat, 09 Aug 2025 17:02:48 GMT

Dear Scott

Thank you for the information. It seems this issue is the same as the one I’m experiencing.

Please let me know if Cisco has resolved the problem, and if so, what steps they took.

Re: Webex Calling audio delays during call initiation

Michalis Papasavva — Mon, 18 Aug 2025 08:03:20 GMT

Hi Scott,

Thanks for the update, please let us know what is TAC final resolution of the issue.

Re: Webex Calling audio delays during call initiation

ckeuk — Thu, 04 Sep 2025 13:43:34 GMT

Would Cisco need to provide the admin password to the phones to make the change in the phone's web gui? I have a support ticket opened with them. But all they want to do is troubleshoot network side again. I know it's their job, but when I have 5 or 6 closed tickets over the year, for the same issue, I figure they would read those previous case first.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Sun, 07 Sep 2025 12:32:24 GMT

Dear Scott,

Thank you for the update.

On my customers, the issue was only resolved after making the following changes:

Set RTP_before_ACK to Yes
Disable ICE
Apply the configuration
Reboot the device

With ICE enabled, the customers still reported delays. I will continue monitoring to confirm whether this process fully resolves the problem. If it does, I will proceed to open a case for all affected customers.

Re: Webex Calling audio delays during call initiation

SCOTT MILLER — Mon, 08 Sep 2025 09:30:54 GMT

No - can be done at Org or phone level, but has to be done by TAC (no customer access).

You can download the PRT logs, and check the XML file to see if the setting is set (on or off - default is off).

Admin access to the phone web GUIs can also be provided by TAC, but they have to generate you a temporary passcode - this is more for if you want to do packet tracing via the web GUI (which I have found not to work amazingly well / kept stopping randomly).

Re: Webex Calling audio delays during call initiation

SCOTT MILLER — Thu, 09 Oct 2025 08:36:52 GMT

For anyone struggling with this issue - see my latest update, on my original response.

Re: Webex Calling audio delays during call initiation

rafiz@bezeqint.co.il — Wed, 15 Oct 2025 07:21:23 GMT

Dear Scott
there is option to change codec priority on Webex calling?

Re: Webex Calling audio delays during call initiation

SCOTT MILLER — Thu, 16 Oct 2025 08:46:58 GMT

Hi Rafiz,

In the device settings, either per device, or per location (this setting cannot be changed at Org level).

Make sure to apply and reboot any devices, to pick the changes up.

Regards
Scott