Cisco Unified IP Phone 500 Series

Cisco Unified IP Phone 500 Series: Cisco Unified IP Phones 521G, 521SG, 524G, and 524SG

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Product Overview

The Cisco ® Unified IP Phone 500 Series is a new group of affordable, entry-level IP phones designed for use with Cisco's Unified Communications 500 Series for Small Business. These phones are an excellent choice for customers making the transition from traditional digital or hybrid key systems (KTS) and private branch exchanges (PBXs) to a system based on the Cisco Unified Communications 500 Series. The Cisco Unified IP Phone 500 Series can easily be integrated into the Cisco Smart Business Communications System. They can be used in cubicles, retail settings, classrooms, breakrooms, lobbies, and manufacturing areas. The phones are optimized to replace traditional voice systems or transition to a next-generation voice solution in a Category 5 (CAT5) wired environment. The 521SG and 524SG phones offer customers the additional option of having a 10/100 switch port for LAN connection to a co-located PC. For customers with no need for a co-located PC, the 521G and 524G models can be used.

Figure 1. Cisco IP Phones 500 Series

The Cisco Unified IP Phones 521G and 521SG are single-line IP phones with two call line appearances. The Cisco Unified IP Phones 524G and 524SG are four-line IP phones with up to eight call line appearances. Four dynamic soft keys on each phone guide you through core business features and functions, while a backlit pixel-based display combines intuitive features, calling information, and device system information to give you information at your fingertips. The Cisco Unified IP Phones 521G, 521SG, 524G, and 524SG can be powered by a network switch with Power over Ethernet (PoE) capability or by an optional power adapter. The phones are in line with Cisco Green, incorporating power efficiency features such as LCD shutoff to save power when the phone is not in use. These phones can also be used with productivity-enhancing features such as directory search and VoiceView Express.


The Cisco Unified IP Phone 500 Series can easily grow with your business. The phones are capable of having new feature functionality added over time via firmware updates. Plus, if you hire an employee or an employee needs to move locations, they can simply plug in their preconfigured phones anywhere on the network, and the network will recognize the change. The phones also provide accessibility features for those with special needs.
Tables 1 through 6 present the features, specifications, and compliance information for the Cisco Unified IP Phone 500 Series. Table 7 provides ordering information, and Table 8 lists optional accessories for these phones.

Table 1. Features



Lighted line keys

Four illuminated call appearance line buttons with tricolor LEDs (Cisco 524G/524SG)

Hold key

Puts current call on hold

Menu key

Accesses call history, directory, network settings, user preferences, reboot, restart, and factory reset

Lighted mute key

Lights up red when the call is on mute, and turns off when mute is removed

Lighted headset key

When pressed, lights up when using a 2.5-mm headset for hands-free calling

Lighted speakerphone key

Activates full-duplex speakerphone; stays lit while speakerphone is on

Lighted message waiting indicator

Lights when there is new voicemail and is visible on the phone chassis above the LCD screen; stays lit until the new voicemail has been processed by the user

Graphical display

Backlit pixel-based display: 128 x 64 monochrome LCD graphical display

Four soft-key buttons and a scroll toggle bar

Dynamically present calling options to the user; the scroll toggle bar allows easy movement through the displayed information

Network features

Cisco Discovery Protocol, IEEE 802.1p/q tagging and switching

Ethernet switch

The Cisco 521SG and 524SG models have a 10/100 PC switch port that enables LAN connectivity to a co-located PC. The system administrator can designate separate virtual LANs (VLANs) (802.1q) for the PC and Cisco Unified IP Phones, providing improved security and reliability of voice and data traffic.

Volume control

Volume-control toggle provides easy decibel-level adjustments of the handset, monitor speaker, and ringer

Single-position foot stand

Optimum display viewing and comfortable use of buttons and keys; the foot stand can be removed for wall mounting with mounting holes located on the base of the phone

Multiple ring tones

More than 24 user-adjustable ring tones

American Disabilities Act (ADA) features

Hearing-aid-compatible (HAC) handset that meets ADA requirements; also meets ADA HAC requirements for a magnetic coupling to approved hearing aids. The phone dialing pad also complies with the ADA.

Signaling protocol support

Supported in Cisco Unified Communications Manager Express versions 4.2.6 and above using Smart Phone Control Protocol (SPCP)

Codec support

G.711a, G.711, G.729a, G.729b, and G.729ab audio-compression codecs

Configuration options

Provisioning of network parameters through Dynamic Host Configuration Protocol (DHCP)

Voice quality

Comfort-noise generation and voice-activity-detection (VAD) programming on a system basis

Table 2. Software and Physical Specifications



Firmware upgrades

Download firmware changes from

Software upgrades

Software upgrade supported using a Trivial File Transfer Protocol (TFTP) server

Dimensions (H x W x D)

6.30 x 7.68 x 7.09 in. (160 x 195 x 180 mm)


2.15 lb (0.9752 kg)

Phone casing composition

Polycarbonate acrylonitrile butadiene styrene (ABS) plastic in textured dark gray with silver-colored bezel

Table 3. Power Options



IEEE 802.3af PoE

Can receive power from IEEE 802.3af-compliant network modules

Local power

Can optionally be powered locally with the AC power adapter listed in Table 4

Table 4. Regional AC Power Supplies

Part Number



Cisco Unified IP Phone 500 Series Universal Power Adapter

Table 5. Temperature Ratings



Operating temperature

41° to ~113°F (5° to ~40°C)

Relative humidity

10 to ~90% noncondensing

Storage temperature

-13° to ~185°F (-25° to ~85°C)

Table 6. Certifications



Regulatory compliance

CE Marking


• Underwriters Laboratories (C-UL) 60950
• EN 60950
• IEC 60950
• AS/NZS 60950

Electromagnetic compatibility

• Federal Communications Commission (FCC) Part 15 (CFR 47) Class B
• ICES-003 Class B
• EN 55022 Class B
• CISPR22 Class B
• AS/NZS CISPR 22 Class B
• CISPR 24
• EN55024
• EN 50082-1
• EN 61000-3-2
• EN 61000-3-3
• EN 61000-6-1


• FCC Part 68 (CFR47) HAC
• TIA 810A

Table 7. Ordering Information

Part Number



Cisco Unified IP Phone 521G, spare


Cisco Unified IP Phone 524G, spare


Cisco Unified IP Phone 521SG, spare (includes 10/100 PC switch port)


Cisco Unified IP Phone 524SG, spare (includes 10/100 PC switch port)

Table 8. Optional Accessories

Part Number



Non-locking wall-mount kit


Spare phone handset


Cisco Unified IP Phones are covered by a Cisco standard one-year hardware warranty.

Service and Support: Protect and Secure Your Investment

Designed for small and medium-sized businesses running the Cisco Smart Business Communications System (SBCS), Cisco SMARTnet ® Service helps you resolve problems and protect and secure your SBCS phones. Delivered by your trusted partner and backed by Cisco, this industry-leading support solution provides greater availability while reducing operating costs.
Cisco SMARTnet Service for your phones, along with Cisco SMARTnet for SBCS for your complete data, voice, and wireless IT system, gives the ultimate in asset protection and is simple, affordable, and complete. Cisco SMARTnet Service offers a range of dependable choices for fast access to business-critical parts and service delivery options according to your preferences and needs. Choose from a variety of hardware replacement options, including premium options such as 2-hour, 4-hour, or next business day, as well as onsite parts replacement and installation. For rapid issue resolution anywhere, anytime, Cisco SMARTnet Service is the right choice for your business communication needs.
The Cisco Unified IP Phone 500 Series can be sold by Cisco partners who hold a Cisco Select Certification or higher, and can be supported by the Cisco Technical Assistance Center (TAC) via SMARTnet contract. For more information about the Cisco Unified IP Phone 500 Series or the Cisco Smart Business Communications System, visit or contact your local partner or account representative.

Table 9. Cisco SMARTnet Services

Part Number



8 x 5 x NBD


8 x 5 x 4


24 x 7 x 4


8 x 5 x NBD


8 x 5 x 4


24 x 7 x 4


8 x 5 x NBD


8 x 5 x 4


24 x 7 x 4


8 x 5 x NBD


8 x 5 x 4


24 x 7 x 4