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Performing a basic reset of a Cisco IP Phone provides a way to recover if the phone experiences an error and provides a way to reset or restore various configuration and security settings.
The following table describes the ways to perform a basic reset. You can reset a phone with any of these operations after the phone has started up. Choose the operation that is appropriate for your situation.
Operation |
Action |
Explanation |
---|---|---|
Restart phone |
Press Settings and choose . |
Resets any user and network setup changes that you have made, but that the phone has not written to its Flash memory, to previously saved settings, then restarts the phone. |
Reset settings |
To reset settings, press Setings and choose . |
Restores phone configuration or settings to factory default. |
Use these steps to reset the phone to factory default settings using the phone keypad.
You can restore your phone to its original manufacturer settings so that the phone can be reconfigured, do it from the phone web page.
You can enter URL in the format: http://<Phone IP>/admin/factory-resetwhere: Phone IP = actual IP address of your phone. /admin = path to access admin page of your phone. factory-reset = command that you need to enter in the phone web page to factory-reset your phone. |
When the phone is not working or doesn't register, a network error or any misconfiguration might be the cause. To identify the cause, add a specific IP address or a domain name to the phone admin page. Then, try to access so that the phone can ping the destination and display the cause.
Enter a URL in the format: http:/<Phone IP>/admin/ping?<ping destination>where: Phone IP = actual IP address of your phone. /admin = path to access admin page of your phone. ping destination = any IP address or domain name that you want to ping. Only alphanumeric characters, ‘-’, and “_” are allowed as the ping destination. Otherwise the phone shows an error on the web page. If the <ping destination> includes spaces, only the first part of the address is used as the pinging destination. For example, “http://<Phone IP>/admin/ping?192.168.1.1 cisco.com” will actually ping 192.168.1.1. |
To measure the voice quality of calls that are sent and received within the network, Cisco IP Phones use these statistical metrics that are based on concealment events. The DSP plays concealment frames to mask frame loss in the voice packet stream.
Concealment Ratio metrics: Show the ratio of concealment frames over total speech frames. An interval conceal ratio is calculated every 3 seconds.
Concealed Second metrics: Show the number of seconds in which the DSP plays concealment frames due to lost frames. A severely "concealed second" is a second in which the DSP plays more than five percent concealment frames.
Note | Concealment ratio and concealment seconds are primary measurements based on frame loss. A Conceal Ratio of zero indicates that the IP network is delivering frames and packets on time with no loss. |
You can access voice quality metrics from the Cisco IP Phone using the Call Statistics screen or remotely by using Streaming Statistics.
When you observe significant and persistent changes to metrics, use the following table for general troubleshooting information.
Metric Change |
Condition |
---|---|
Conceal Ratio and Conceal Seconds increase significantly |
Network impairment from packet loss or high jitter. |
Conceal Ratio is near or at zero, but the voice quality is poor. |
Check packet transmit (TxCnt) and packet receive (RxCnt) counters to verify that voice packets are flowing. |
MOS LQK scores decrease significantly |
Network impairment from packet loss or high jitter levels:
Cross-check the conceal ratio and conceal seconds for evidence of packet loss and jitter. |
MOS LQK scores increase significantly |
Note | Voice quality metrics do not account for noise or distortion, only frame loss. |
You can capture voice quality metrics for Voice over Internet Protocol (VoIP) sessions with a Session Initiation Protocol (SIP) event package. Voice call quality information derived from RTP and call information from SIP is conveyed from a User Agent (UA) in a session (reporter) to a third party (collector).
The Cisco IP phone uses User Datagram Protocol (UDP) to send a SIP PUBLISH message to a collector server.
Currently, only the basic call scenario supports voice quality reporting. A basic call can be a peer to peer incoming or outgoing call. The phone sends the SIP Publish message when a call ends.
The voice quality metrics use Mean Opinion Score (MOS) to rate the quality. A MOS rating of 1 is the lowest quality; a MOS rating of 5 is the highest quality. The following table gives a description of the codecs and MOS scores. For other codecs, the phone does not send the SIP Publish message.
Codec |
Complexity and Description |
MOS |
Minimum Call Duration for Valid MOS Value |
---|---|---|---|
G.711 (A-law and u-law) |
Very low complexity. Supports uncompressed 64 kbps digitized voice transmission at one to ten 5 ms voice frames-per-packet. This codec provides the highest voice quality and uses the most bandwidth of any of the available codecs. |
A minimum value of 4.1 indicates good voice quality. |
10 seconds |
G.729A |
Low to medium complexity. |
A minimum value of 3.5 indicates good voice quality. |
30 seconds |
G.729AB |
Contains the same reduced complexity modifications present in the G.729A. |
A minimum value of 3.5 indicates good voice quality. |
30 seconds |
You can enable voice quality reporting on the phone with the web interface. Each extension on a phone has a separate voice quality report. For each extension on the phone, use the corresponding Voice Quality Report Address field to configure the generation of voice quality report.
Step 1 | On the Configuration Utility page, select . |
Step 2 | In SIP Settings, enter a value in the Voice Quality Report Address x field. You can enter either a domain name or an IP address in this field. You can also add a port number along with the domain name or an IP address in this field. If you do not enter a port number, the value of the SIP UDP Port (5060) is used by default. If the collector server URL parameter is blank, a SIP PUBLISH message is not sent out. |
Step 3 | Click Submit All Changes. |
To clean your Cisco IP Phone, use only a dry soft cloth to gently wipe the phone and the phone screen. Do not apply liquids or powders directly to the phone. As with all non-weatherproof electronics, liquids and powders can damage the components and cause failures.
When the phone is in sleep mode, the screen is blank and the Select button is not lit. When the phone is in this condition, you can clean the screen, as long as you know that the phone will remain asleep until after you finish cleaning.
The Info tab shows information about all phone extensions, including phone statistics and the registration status. |
The phone stores the most recent five reasons that the phone was refreshed or rebooted. When the phone is reset to factory defaults, this information is deleted.
The following table describes the reboot and refresh reasons for the Cisco IP Phone.
The reboot was a result of an upgrade operation (regardless whether the upgrade completed or failed). |
|
The reboot was the result of changes made to parameter values by using the IP phone screen or phone web user interface, or as a result of synchronization. |
|
The reboot was triggered as a result of remote customization. |
|
The reboot was triggered after the phone IP address changed. |
On the Info > System Status page, the Reboot History section displays the device reboot history, the five most recent reboot dates and times, and a reason for the reboot. Each field displays the reason for the reboot and a time stamp that indicates when the reboot took place.
Reboot Reason 1: [08/13/14 06:12:38] User Triggered Reboot Reason 2: [08/10/14 10:30:10] Provisioning Reboot Reason 3: [08/10/14 10:28:20] Upgrade
The reboot history displays in reverse chronological order; the reason for the most recent reboot displays in Reboot Reason 1.
Reboot History is located under menu. In the Reboot History window, the reboot entries displays in reverse chronological order, similar to the sequence that displays on the phone web user interface.
The reboot history is stored in the Status Dump file (http://<phone_IP_address>/admin/status.xml).
In this file, tags Reboot_Reason_1 to Reboot_Reason_3 store the reboot history, as shown in this example:
<Reboot_History> <Reboot_Reason_1>[08/10/14 14:03:43]Provisioning</Reboot_Reason_1> <Reboot_Reason_2>[08/10/14 13:58:15]Provisioning</Reboot_Reason_2> <Reboot_Reason_3>[08/10/14 12:08:58]Provisioning</Reboot_Reason_3> <Reboot_Reason_4> <Reboot_Reason_5> <Reboot_History/>
Anything that degrades network performance can affect Cisco IP Phone voice and video quality, and in some cases, can cause a call to drop. Sources of network degradation can include, but are not limited to, the following activities:
Administrative tasks, such as an internal port scan or security scan
Attacks that occur on your network, such as a Denial of Service attack
To reduce or eliminate any adverse effects to the phones, schedule administrative network tasks during a time when the phones are not being used or exclude the phones from testing.