Does the SoundPoint IP 550 support an expansion module?

Yes — the SoundPoint IP Backlit Expansion Module (sidecar). Each module adds 14 line keys with status LEDs, and you can chain up to three modules off a single 550. The expansion module also provisions on voip.army's legacy network.

Is the SoundPoint IP 550 still supported on voip.army?

Yes — UCS firmware 4.0.15 on our legacy provisioning VLAN. Provisioning traffic stays isolated because the phone predates TLS 1.2; call media (SRTP) and SIP signaling are normal.

SoundPoint IP 550 vs IP 650 — difference?

The 650 added a second Ethernet port (so it has dual ports for LAN + PC pass-through), gigabit Ethernet, and a slightly higher line count (six lines vs four). Same display class, same expansion module support.

What's the modern equivalent?

The Poly VVX 411 — twelve-line color desk phone with gigabit, expansion module support, and current UCS firmware. Or the VVX 350 if you want greyscale and a lower price point.

Polycom · SoundPoint IP · legacy fleet

Polycom SoundPoint IP 550Still works. Still supported.

The SoundPoint IP 550 is the HD-voice four-line manager phone Polycom shipped in the late 2000s — larger 320×160 display, expansion module support, full SoundPoint chassis. EOL'd 2015; still in heavy production use and fully supported on voip.army.

Display

graphical LCD

SIP accounts

4 lines

Ethernet

Dual 10/100

Type

Desk phone

EOL year

2015

Condition

Refurbished / pre-owned

$89 refurbished

or rent for $7.99/mo — month-to-month, return anytime

Pre-owned, tested, re-flashed for voip.army — 30-day return

Order a SoundPoint IP 550 Rent for $7.99/mo Datasheet (PDF) ↓

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Polycom SoundPoint IP 550 VoIP phone — front view with handset and dialpad — Polycom SoundPoint IP 550

Why we still support the SoundPoint IP 550.

The SoundPoint IP 550 was the volume manager-tier phone in the late 2000s and early 2010s. Four SIP lines, HD voice via G.722, a larger 320×160 monochrome display that fit BLF labels comfortably, and — importantly — support for the SoundPoint IP Expansion Module sidecar for receptionists who needed more keys.

Released 2007, EOL'd 2015. We see 550s in fleet quantities at law firms, financial services, and any vertical that bought into the SoundPoint family early. The hardware ages well; we regularly onboard 550s that have been in continuous service for fifteen-plus years.

For existing fleets, the 550 onboards onto voip.army's legacy provisioning VLAN running UCS firmware 4.0.15. SoundPoint IP Expansion Modules also onboard and work normally. For new orders the closest current equivalent is the VVX 350 or VVX 411 — both add gigabit Ethernet and current firmware.

Full technical specifications.

Display & user interface
Display	Backlit 320×160 pixel monochrome graphical LCD
Line keys	4 line keys with dual-color LEDs
Soft keys	Context-sensitive under the display
VoIP & SIP
SIP accounts	4
SIP protocols	SIP v2 (RFC 3261), supported on voip.army's legacy provisioning VLAN with UCS firmware 4.0.15
Codecs	G.711, G.722, G.729AB, G.726, iLBC
Audio
Speaker	Full-duplex with Polycom Acoustic Clarity
HD voice	G.722 wideband on handset/speaker
Headset	RJ9 headset jack
Connectivity
Ethernet	Dual 10/100 Mbps
PoE	IEEE 802.3af Class 2
Power & physical
Power source	PoE 802.3af Class 2 (preferred) or Polycom power adapter (sold separately)
Weight	1.18 kg
Dimensions	265 × 175 × 195 mm
Wall-mountable	Yes
Lifecycle status
EOL year	2015
Firmware on voip.army	Polycom UCS 4.0.15 (legacy provisioning VLAN)
voip.army stock	Refurbished / pre-owned, tested and re-flashed

How it works on voip.army.

The SoundPoint IP 550 runs Polycom UCS firmware 4.0.15 — the last release that supports this hardware. It onboards onto voip.army the same way as any current phone, just on our legacy provisioning VLAN because the phone's TLS stack predates modern web standards. Call quality is normal SRTP.

60s

Time from plug-in to first call

Boot, fetch config from our provisioning server, register, ready. About one minute on a normal internet connection.

SIP accounts on one phone

Run up to 4 simultaneous SIP registrations. Each line key has a dual-color LED for status.

Per-device onboarding fees

Bringing your own? Send us the MAC, factory-reset, plug in. No charge to add it to the fleet.

4.0.15

UCS firmware version

Last firmware Polycom shipped for this phone (2018). Still works perfectly on voip.army; provisions over our isolated legacy VLAN because the phone can't speak TLS 1.2.

100m

Ethernet to the workstation

PC pass-through port on the back lets you daisy-chain a single ethernet drop to phone and computer.

802.3af

PoE class

Class 2. Any 802.3af-compliant switch from the last 15 years will power it without issue.

Onboarding a fleet of SoundPoint IP 550s?

Send us a CSV of MAC addresses. We add them to the provisioning server, you factory-reset and plug in, they pick up their voip.army config within a minute.

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