How to Set Up the Cisco IP Phone 7800 and Cisco IP Phone 8800 Series IP Phones

This guide explains how to set up the Cisco IP Phone 7800 series and Cisco IP Phone 8800 series IP phones.

This guide will apply for the following handsets:

  • Cisco IP Phone 7811
  • Cisco IP Phone 7821
  • Cisco IP Phone 7841
  • Cisco IP Phone 7811
  • Cisco IP Phone 8861
  • Cisco IP Phone 8831
  • Cisco IP Phone 8832
  • Cisco IP Phone 8845
  • Cisco IP Phone 8851
  • Cisco IP Phone 8861
  • Cisco IP Phone 8865

For more information on the Cisco range of IP phones, please visit the Cisco phones product page.

  1. Obtain the handset IP address.
    Press the page (Setup) button, scroll down to 9. Network and note the CurrentIP
  2. Type the IP address into your web browser.
  3. Once the page has loaded, press Admin Login then press advanced
  4. Go to the SIP tab
  5. Scroll down to RTP Parameters and sets RTP Packet Size to 0.020 :!:This is often overlooked.
  6. Scroll down to NAT Support Parameters and set Handle VIA rport and Insert VIA rport to no
  7. Go to the Ext 1 tab (Or whichever Ext you are using)
    • Under General set Line Enable to yes
    • Under NAT Settings set NAT Mapping and NAT Keep Alive to yes
    • Under SIP Settings set SIP Transport to UDP
    • Under Proxy and Registration enter the following settings. You will need to reference your welcome pack.
      • Set Proxy to the SIP Proxy/Registrar Server provided in your welcome email
      • Set Register to yes
    • Under Subscriber Information enter the following settings. You will need to reference your welcome pack.
      • Put your name into Display Name. What is entered here is arbitrary.
      • Put your SIP Username (extension number) into the User ID and Auth ID fields. This is provided in your welcome pack.
      • Put your provided SIP password (also referred to as SIP Secret) into the Password field. This is provided in your welcome pack.
      • Set Use Auth ID to yes
    • Under Audio Configuration set Preferred Codec to G711a or set to G722 if on SureVoIP Multi-User Hosted.
    • Put the following into Dial Plan
  8. Click Submit All Changes
  9. Once the phone has rebooted and is back online, go to the Info tab and scroll down to Ext 1 Status and check the Registration State shows Registered

Line Keys

The line keys, along the display, can be programmed to allow you to select which line you wish to use to make a call (if you use your phone with more than one account).

Under the Phone tab, select which extension each line key should correspond to. You can give each a short name that will appear alongside the button on the display.

Or if you have buttons spare, they can be set up to be BLF + speed dial + call pickup buttons.

This allows you to monitor the state of another extension (if it is ringing, busy or available), quickly dial that extension, or pick up an extension that is ringing (and there is nobody there).

  1. First, click the advanced button on the top-right.
  2. Go to the Attendant Console tab
    • Set Server Type to Asterisk
    • Set Attendant Console Call Pickup Code to **#
  3. Go to the Phone tab
    • For each button you wish to use as a BLF+SD+CP key, set Extension to Disabled
    • Type in something short yet relevant into the Short Name field, such as the person's name
    • In Extended Function put in: fnc=sd+blf+cp;sub=XXXX@$PROXY
      XXXX is the extension you wish to monitor
    • Alternatively, for Speed Dial only to an external number, simply put in: fnc=sd;ext=XXXXXXXXXXX@$PROXY
      Where XXXXXXXXXXX is the number to dial.
  4. When the monitored extension is available, it shows green. Red when on a call or busy. Blinking red when ringing. Orange if there is an error in the syntax.
  5. It is highly recommended to remove any conflicting Vertical Service Activation Codes in the Regional tab. Simply clear them out and click Submit All Changes.
  6. Please note that at least 1 line key is required for the actual line, otherwise your phone will be unable to function properly.


To program the Voicemail key to dial your voicemail, go to the Phone tab, and in the Voice Mail Number field put in *97

Additional Settings

These are optional settings, but are highly recommended to get the best experience out of your phone.

Set Time Servers

In System tab, under Optional Network Configuration

  • Set NTP Enable to yes
  • Set Primary NTP Server to
  • Set Secondary NTP Server to

Use the above as an example as your system administrator may be able to provide you with your company's internal NTP servers.

In Regional tab, under Miscellaneous

  • Set Time Zone to GMT
  • Set Daylight Savings Rule to start=3/-1/7/2:0:0;end=10/-1/7/2:0:0;save=1:0:0
  • Set Ignore DHCP Time Offset to no
  • Set Locale to en-GB

If registration is failing, check over the settings entered above.

Ensure SIP ALG is disabled on your router. See this page for further information.

If the Status page shows timeout, check over your firewall settings.

If you are still having trouble registering, contact SureVoIP Technical Support.