Cisco IP Phone SPA508G User Manual

The Cisco SPA508G is a feature-rich 8-line IP phone designed for small to medium-sized businesses. It offers high-quality audio, a large graphical LCD, support for Power over Ethernet (PoE), and integration with Cisco Unified Communications Manager and BroadWorks platforms. This manual covers key sections for safety, features, installation, configuration, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting to Network 7. Making and Receiving Calls 8. Advanced Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Large backlit graphical LCD, 8 line keys with LEDs, 4-way navigation cluster, dedicated buttons for hold, transfer, conference, voicemail, speakerphone, headset, and mute.

Feature	Description
Display	132 x 65 pixel graphical LCD with backlight
Lines/Extensions	8 SIP lines/accounts
Network Ports	Two 10/100 Ethernet ports (LAN, PC)
Power	IEEE 802.3af PoE or external power adapter
Audio	High-quality handset and speakerphone, headset port
Codecs	G.711, G.729A, G.726, iLBC
Protocols	SIP (Session Initiation Protocol)
Conference	Built-in 3-way conference bridge
Security	Secure call support via SRTP and TLS
Firmware	Field upgradable via TFTP/HTTP/HTTPS

Installation

Unpack and inspect contents. Place phone on a stable, flat surface.

Connect to Network: Plug an Ethernet cable from your network switch/router into the "LAN" port on the phone.
Connect a Computer (Optional): Plug an Ethernet cable from the "PC" port on the phone to your computer's network port.
Apply Power: Use Power over Ethernet (PoE) from your switch, or connect the included power adapter to the "PWR" port and an AC outlet.
Connect Handset: Plug the coiled handset cord into the jack marked with a handset icon.
Connect Headset (Optional): Plug a 2.5mm headset into the jack marked with a headset icon.

WARNING! Use only the provided or approved power adapter. Ensure cables are not pinched or damaged.

First-Time Setup

Power on the phone; it will attempt to boot and obtain network configuration via DHCP.

Check Network Registration: Observe the LCD. It should display the date/time and show "Line 1" as registered to your VoIP service provider.
Configure via Web Interface (Advanced): Obtain the phone's IP address (press the "Settings" button, navigate to "Status" > "Network Status"). Enter this IP in a web browser to access the administration interface.
Enter Account Details: In the web interface, under the "Line" tabs, enter the SIP server, username, password, and other details provided by your service provider.
Provision Firmware: The phone may automatically download and update its firmware from the configured provisioning server.
Test Basic Functions: Lift the handset to get a dial tone. Make a test call.

CAUTION! Do not unplug the phone during firmware upgrade. Ensure network settings are correct for your environment.

Specifications

Model: Cisco SPA508G IP Phone.
Display: 132 x 65 pixel graphical LCD, white backlight.
Lines: 8 independently configurable SIP lines.
Network: Dual 10/100 Mbps Ethernet ports with integrated switch.
Power: IEEE 802.3af Class 2 PoE or 5V DC, 2.0A external adapter.
Audio Features: Full-duplex speakerphone, wideband audio support, acoustic echo cancellation.
Telephony Features:Hold, transfer, 3-way conference, call waiting, caller ID, mute, redial, forward.
Supported Codecs: G.711a/u, G.729a/b, G.726, iLBC.

Protocols: SIP v2 (RFC3261), TCP/IP/UDP, ARP, ICMP, DNS A/NAPTR/SRV, DHCP, TFTP, HTTP/HTTPS, SNMP, RTP/RTCP, SRTP, TLS.

Physical Dimensions: 9.25" (W) x 9.0" (D) x 7.0" (H).

Controls and Settings

Access settings via the LCD menu using the 4-way navigation button or via the web-based administration interface.

Front Panel Buttons: Speakerphone, Headset, Mute, Navigation Cluster (Up/Down/Left/Right/OK), Settings, Volume Rocker, 8 Line Keys, Hold, Transfer, Conference, Voicemail.

LCD Menu (Settings Button): Network Status, Firmware Version, SIP Status, Call History, Phone Settings (Time, Display, Audio, Ring Tones).

Web Interface (Advanced): SIP Lines, Network (DHCP, Static IP, VLAN), Regional (Language, Time Zone), Security, Voice (Audio Codecs, QoS), System (Provisioning, Firmware Upgrade). Default admin password is often blank or "admin".

Connecting to Network

Primary connection is via the LAN port. The PC port allows daisy-chaining a computer.

Ensure network switch/router is powered on and providing data (and PoE if used).

Use standard CAT5e or higher Ethernet cables.

For VLAN segmentation, configure the phone's VLAN settings via the web interface (e.g., 802.1Q VLAN ID for voice).

Select appropriate network configuration: DHCP (recommended) or Static IP.

Tip: If using PoE, verify your switch provides sufficient power (IEEE 802.3af). The phone will not power on if PoE is insufficient or non-standard.

Making and Receiving Calls

Basic telephony operations.

Make a Call: Lift handset or press Speaker/Headset. Dial number using the keypad. Press Dial softkey or wait for inter-digit timeout.

Answer a Call: Lift handset, press Speaker, press Headset, or press the flashing line key.

End a Call: Hang up handset, press Speaker/Headset button again, or press the "End Call" softkey.

Hold: Press the "Hold" button during a call. Press the line key or "Resume" softkey to retrieve.

Transfer (Blind): During a call, press "Transfer". Dial the target number. Press "Transfer" again to complete.

Transfer (Attended): During a call, press "Transfer". Dial target and wait for answer. Announce call, then press "Transfer" to complete.

3-Way Conference: During first call, press "Conference". Dial second party. When connected, press "Conference" again to merge all parties.

Voicemail: Press the "Messages" button or dial your voicemail access number (e.g., *98).

WARNING! Emergency calls (e.g., 911) may require specific configuration. Confirm with your service provider.

Advanced Features

Call Forwarding: Configure via web interface or dial codes (e.g., *72 to activate). Call Waiting: Enabled by default; hear a beep during a call. Press "Answer" softkey to put first call on hold and answer second. Shared Line Appearance: Configure multiple phones to ring for the same extension. Phone Lock: Set a PIN via the settings menu to prevent unauthorized use. Personalized Ring Tones: Assign different rings per line via the web interface.

Care & Cleaning

Disconnect power before cleaning. Use a soft, dry, lint-free cloth. For stubborn marks, slightly dampen the cloth with water. Do not use abrasive cleaners, solvents, or sprays directly on the phone.

CAUTION! Never allow liquid to enter any openings. Keep the phone away from excessive heat, humidity, and dust.

Regulatory Information

FCC Part 15: This device complies with Part 15 of the FCC Rules. Operation is subject to the condition that this device does not cause harmful interference. ICES-003: Complies with Canadian ICES-003 Class B limits. CE Mark: Conforms to European EMC and Low Voltage Directives. For full regulatory statements and declarations of conformity, visit Cisco's compliance website. This product may be covered by one or more Cisco patents. For support, contact your service provider or visit www.cisco.com/go/sbssupport.

Troubleshooting

Symptom Possible Cause Corrective Action

No power, display blank Power not connected Check PoE switch or power adapter connection. Try a different outlet or Ethernet cable known to provide PoE.

No dial tone Network or SIP registration issue Check Ethernet cable/LEDs. Verify IP address on screen. Confirm SIP credentials and server address are correct in web interface.

One-way or no audio Network QoS/Firewall Check router/firewall for SIP ALG settings; disable if possible. Verify QoS (Priority/DSCP) settings for voice traffic.

Can't access web interface Network/IP address Confirm phone's IP address from LCD. Ensure your computer is on the same network subnet.

Call quality issues (echo, static) Audio settings or network Adjust audio gain settings in web interface. Test with a different handset/headset. Check for network packet loss/jitter.

Phone not upgrading firmware Provisioning server Verify TFTP/HTTP server address and filename. Check network connectivity to the server.

Factory Reset: Press and hold the "#" key while powering on the phone (or via web interface) to restore factory defaults. This will erase all configuration.

Service: Contact your VoIP service provider for configuration support. For hardware issues, refer to Cisco or your reseller's warranty policy.

Cisco IP Phone SPA508G User Manual © - All Rights Reserved 2025

Symptom	Possible Cause	Corrective Action
No power, display blank	Power not connected	Check PoE switch or power adapter connection. Try a different outlet or Ethernet cable known to provide PoE.
No dial tone	Network or SIP registration issue	Check Ethernet cable/LEDs. Verify IP address on screen. Confirm SIP credentials and server address are correct in web interface.
One-way or no audio	Network QoS/Firewall	Check router/firewall for SIP ALG settings; disable if possible. Verify QoS (Priority/DSCP) settings for voice traffic.
Can't access web interface	Network/IP address	Confirm phone's IP address from LCD. Ensure your computer is on the same network subnet.
Call quality issues (echo, static)	Audio settings or network	Adjust audio gain settings in web interface. Test with a different handset/headset. Check for network packet loss/jitter.
Phone not upgrading firmware	Provisioning server	Verify TFTP/HTTP server address and filename. Check network connectivity to the server.