https://www.cisco.com/en/US/docs/voice_ip_comm/cucm/admin/3_1_2/ccmcfg/b03spchr.html

https://www.ciscopress.com/articles/article.asp?p=357102&seqNum=7#:~:text=If%20Scavenger
%20and%20Bulk%20traffic,illustrated%20in%20Figure%2012%2D10

A SIP Dial Rule in CUCM allows administrators to define specific dialing behaviors for SIP phones. By creating a SIP Dial Rule with a PLAR configuration, you can set a phone to automatically dial a predetermined number when the handset goes off-hook.
Configuration Steps:
1. Create a SIP Dial Rule:
- Navigate to Call Routing > Dial Rules > SIP Dial Rules in the CUCM Administration interface.
- Click Add New.
- Provide a description for the dial rule.
- Click Add Plar to define the PLAR behavior.
- Specify the line button (e.g., Button 1) and the destination number for the PLAR.
- Save the configuration.
2. Assign the SIP Dial Rule to the SIP Phone:
- Navigate to Device > Phone and select the desired SIP phone.
- In the phone configuration page, locate the SIP Dial Rules field.
- Select the SIP Dial Rule you created from the dropdown menu.
- Save and apply the configuration.
By following these steps, the SIP phone will automatically dial the specified number when the handset is lifted, implementing the PLAR functionality.

Cisco Unified Communications Manager Administration provides the clusterwide service parameter, Drop Ad Hoc Conference, to allow the prevention of toll fraud (where an internal conference controller disconnects from the conference while outside callers remain connected).
The service parameter settings specify conditions under which an ad hoc conference gets dropped.
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/10_0_1/ccmsys/CUCM_BK_SE5FCFB6_00_cucm-system-guide-100/CUCM_BK_SE5FCFB6_00_cucm-system-guide-100_chapter_011000.html#CUCM_TK_DFC66444_00

Low Latency Queueing provides a strict priority queue for real-time voice traffic, ensuring VoIP packets are transmitted first during congestion, which significantly reduces packet drops and preserves voice quality.