Webex Returns a ‘SIP 599 Incoming call denied’ Response when Attempting to Join a Meeting From a Video System
When attempting to join a meeting through a video device, you may receive the error message “SIP 599 Incoming call denied.”
When I attempt to attend the meeting via my video device, I get a response that says “SIP 599 Incoming call denied.”
Why do I see calls to Webex with SIP 599 replies in my call history?
Why am I unable to connect to Webex Meetings using the video device or client that I have that uses the SIP or H.323 protocol?
How can I determine whether or not Webex has blacklisted my IP address?
Cisco Webex makes use of a number of solutions in order to defend the cloud infrastructure and services against assaults and abuse, both of which have the potential to adversely affect customer meetings. Cisco Webex makes use of third-party block-lists as part of this endeavor and compares the IP addresses of incoming calls (calls flowing to Webex from on-prem) against these block-lists.
The call is denied with a SIP response code of 599 and the reason text ‘Incoming call denied’ if it is determined that the incoming call matches an entry on a block list. Any further attempts to make the same call will also be denied service, regardless of whether they use the same IP addresses or not.
You can use the check utilities that can be found on the following page to determine whether or not one of your IP addresses is on one of the block lists:
The VoIP Block-list maintained by ScopServ International Inc. can be found at https://voipbl.org/.
Note that it is possible to block only one IP address or many IP addresses, which would cause calls to fail even if they travel through other devices using different IP addresses. This can happen even if the blocked IP address was the only one.
Be sure to check any and all Internet-routable IP addresses that your calls might pass through, and then use the checking tools on the page above to submit a request for the blocking to be removed. For instance, if you are deploying a Cisco Expressway-Edge (Expressway-E) cluster, make sure to check all of the external IP addresses. These IP addresses are commonly referred to as the LAN2 IP address, or the static NAT IP address. Please wait up to an hour for any caching services to expire before attempting to make a new call after the block-list provider has confirmed that your IP addresses have been unblocked. This is to ensure that any new calls are successful.
If the problem continues, you should contact the technical support team. Please refer to the following article if you require assistance: WBX162 – How Do I Contact Webex Customer Services or Technical Support?
