Cisco 8800 Series, Manual

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As part of both GET and POST requests, the phone automatically includes basic identifying information in
the User-Agent field of the request header. This information conveys the manufacturer, product name, current
firmware version, and product serial number of the device.
The following example is the User-Agent request field from a CP-8841-3PCC:
User-Agent: Cisco-CP-8841-3PCC/11.0 (00562b043615)
User Agent is configurable, and the phone uses this the value if it has not be configured (still at default).
When the phone is configured to resync to a configuration profile by using HTTP, it is recommended that
HTTPS be used or the profile be encrypted to protect confidential information. Encrypted profiles that the
phone downloads by using HTTP avoid the danger of exposing confidential information that is contained in
the configuration profile. This resync mode produces a lower computational load on the provisioning server
when compared to using HTTPS.
The phone can decrypt profiles encrypted with one of these encryption methods:
• AES-256-CBC encryption
• RFC-8188 based encryption with AES-128-GCM ciphering
The phones support HTTP Version 1.0, HTTP Version 1.1, and Chunk Encoding when HTTP Version 1.1 is
the negotiated transport protocol. Note
HTTP Status Code Handling on Resync and Upgrade
The phone supports HTTP response for remote provisioning (Resync). Current phone behavior is categorized
in three ways:
• A—Success, where the “Resync Periodic” and “Resync Random Delay” values determine subsequent
requests.
• B—Failure when File Not Found or corrupt profile. The “Resync Error Retry Delay” value determines
subsequent requests.
• C—Other failure when a bad URL or IP address causes a connection error. The “Resync Error Retry
Delay” value determines subsequent requests.
Table 3: Phone Behavior for HTTP Responses
Phone Behavior Description HTTP Status Code
Retry request immediately with new
location. This and future requests should be directed
to a new location.
301 Moved
Permanently
Retry request immediately with new
location. Known as Temporarily Moved. 302 Found
C Other 3xx responses not processed. 3xx
Cisco IP Phone 8800 Series Multiplatform Phone Administration Guide for Release 11.3(1) and Later
36
Cisco IP Phone Provisioning
HTTP Status Code Handling on Resync and Upgrade