Grandstream GRP2603 Essential IP Phone

The Grandstream GRP2603 is the point in the essential range where the specification stops feeling entry-level. Three line keys carry up to six SIP accounts, the display grows to a 2.7-inch backlit LCD, and the network ports move up to full Gigabit — so the phone no longer throttles the PC plugged in behind it.

That makes it a sensible default for main office desks, particularly in businesses that have already moved to Gigabit cabling and do not want a 100 Mbps bottleneck at every workstation. Three call appearances give users room to hold one call, take another and still have a line free, while the familiar GRP management tooling keeps rollouts and firmware updates predictable. The GRP2603P variant adds integrated 802.3af PoE if you would rather not run mains adapters to every desk.

Key features

• Three lines with six SIP accounts — three simultaneous call appearances and plenty of registration headroom
• Dual-colour LED line keys — instant visual state for ringing, active and held calls
• 2.7-inch 132 × 64 backlit LCD — more room for caller detail and menu context than the GRP2601 and GRP2602
• Gigabit Ethernet on both ports — the desktop PC behind the phone keeps its full network speed
• 5-way audio conferencing — handle multi-party calls without the PBX bridge
• Four XML programmable soft keys — context-sensitive functions plus five navigation keys
• Wideband HD audio — G.722 and Opus alongside the usual narrowband codecs
• RJ9 headset jack with EHS — Plantronics, Jabra and Sennheiser hook switch support
• PoE option — the GRP2603P draws IEEE 802.3af Class 1 power from the switch
• Secure boot and encrypted storage — enterprise-grade protection for provisioned credentials

Technical specification

Telephony

• 3 lines, 6 SIP accounts, up to 3 call appearances
• 5-way audio conferencing
• Codecs: G.711µ/a-law, G.722 (wideband), G.723.1, G.726, G.729A/B, iLBC, Opus

Display and controls

• 132 × 64 pixel, 2.7-inch backlit graphical LCD
• 3 line keys with dual-colour LEDs
• 4 XML programmable context-sensitive soft keys
• 5 navigation and menu keys

Network

• Dual switched auto-negotiating 10/100/1000 Mbps Gigabit Ethernet ports
• Integrated PoE on the GRP2603P variant, IEEE 802.3af Class 1, 3.84W

Audio and headset

• HD handset and speakerphone
• RJ9 headset jack with EHS for Plantronics, Jabra and Sennheiser

Power and physical

• Universal power supply, +5VDC 600mA output
• Dimensions: 214 × 206 × 68 mm with handset

Security and management

• Secure boot, dual firmware images, encrypted data storage
• SRTP and TLS encryption
• GDMS and TR-069 mass provisioning

Datasheet

Download the official Grandstream GRP2603 datasheet (PDF)

Works with

• Grandstream GRP2604 — same lines and accounts plus 10 dedicated BLF keys
• PSU for GRP260x — mains adapter for the non-PoE model
• Grandstream GWN7801P PoE switch — power the GRP2603P from the network
• Replacement curly cord
• All Grandstream IP phones
• IP PBX solutions
• Grandstream UCM6302 IP PBX — a compact on-site UCM to register the GRP2603 to

Frequently asked questions

Does the GRP2603 have Gigabit Ethernet?

Yes. Both switched ports run at 10/100/1000 Mbps, so a PC connected through the phone is not limited to 100 Mbps as it would be on the GRP2601 or GRP2602.

How many calls can be active at once?

The phone provides three call appearances across its three line keys, with six SIP accounts available for registration.

Do I need the GRP2603P?

Only if you want the phone powered over the network cable. The GRP2603P is otherwise identical and draws IEEE 802.3af Class 1 power, which most PoE switches supply comfortably.

Is there a BLF version for monitoring colleagues?

Yes — the GRP2604 shares this specification and adds ten dedicated BLF keys, which suits reception and dispatch positions.

Will it register to a hosted platform?

Yes. It is a standard SIP handset and is commonly provisioned against hosted UK platforms as well as on-premise systems.

Need advice on lines versus BLF keys for your team? Call 0333 242 1314 or email sales@clisecure.com.