Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager - Technical Details

Publisher

Cisco Systems

URL

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cuipph/8800-series/english/adminguide/P881_BK_C136782F_00_cisco-ip-phone-8800_series/P881_BK_C136782F_00_cisco-ip-phone-8811-8841_chapter_01.html

Published

2025-11-06

Updated

unknown

Accessed

2026-09-24

HTTP status

200

License

Cisco copyright; all rights reserved; no-redistribution; short excerpts and locators only

Source notes citing this source

• The 8800 administration guide states that autoregistration is disabled when the CTL client is configured, so phones must then be added to the database manually. disputed in context
• In the 8800 startup process the phone requests the CTL file first and then the ITL file, both from the TFTP server. in context
• After obtaining its configuration file, the phone attempts to connect to the highest-priority Unified CM node on the list, using TLS when secure and TCP when nonsecure. in context
• If DHCP does not supply a TFTP server address, the TFTP server must be configured locally on the phone, which then contacts it directly. in context
• The 8800 Series phone uses CDP to exchange the auxiliary VLAN ID, power details and QoS information with a Cisco Catalyst switch, and supports LLDP-MED for voice VLAN configuration, device discovery, power and inventory management. in context
• During startup an 8800 Series phone configures its VLAN, obtains an IP address, accesses a TFTP server, requests the CTL file, requests the ITL file, requests its configuration file, and then contacts Unified CM. in context
• A phone with a statically defined IP address must have its TFTP server configured locally on the phone; otherwise the DHCP server directs it to the TFTP server. in context
• When connected to a Cisco Catalyst switch, the switch tells the phone the voice VLAN, and the phone needs its VLAN membership before it makes its DHCP request. in context
• During startup, a Cisco IP Phone 8800 connected to a Cisco Catalyst switch is told the voice VLAN defined on the switch before it requests an IP address. in context
• When autoregistration is enabled and the phone has not been added to the Unified CM database, the phone fetches the default configuration file XmlDefault.cnf.xml from TFTP. in context
• Cisco IP Phones 8861 and 8865 are PoE Class 4 devices and need a Class 4 capable switch or line card to support their extra features. in context
• Cisco's 8800 admin guide for Unified CM recommends DHCP custom option 150, set to the TFTP server IP address, and falls back to DHCP option 66 if option 150 cannot be used. in context
• If an administrator disables on the phone the protocol the switch locked power negotiation to, the Cisco 8800 phone cannot power accessories, because the switch ignores power requests in the other protocol. in context
• After a Cisco 8800 phone reboots, the switch locks power negotiation to whichever protocol, CDP or LLDP, carries the phone's first power TLV. in context

Cite this source record

APA

WarmTransfer. (2025, November 6). Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager - Technical Details. WarmTransfer. https://warmtransfer.net/knowledge/sources/cisco-8800-admin-guide-cucm-technical-details

BibTeX

@misc{warmtransfer-cisco-8800-admin-guide-cucm-technical-details,
  title  = {Cisco IP Phone 8800 Series Administration Guide for Cisco Unified Communications Manager - Technical Details},
  author = {{WarmTransfer}},
  year   = {2025},
  url    = {https://warmtransfer.net/knowledge/sources/cisco-8800-admin-guide-cucm-technical-details},
  note   = {Cisco Systems, accessed 2026-09-24}
}