Grandstream GRP2603P Carrier-Grade IP Phone

The Grandstream GRP2603P is the three-line essential desk phone with Power over Ethernet built in. It is the model most people should actually buy for a main office desk: three line keys carrying up to six SIP accounts, a 2.7-inch backlit display, Gigabit ports on both sides and no adapter to find a socket for.

The step up from a two-line phone is less about the third line than about what comes with it. The display grows enough to show a full name and number rather than a truncated one, and the network ports move to Gigabit — so the PC sharing that wall socket is no longer capped at a tenth of its link speed. On a desk with a computer behind the phone, that is the specification that matters.

PoE means one cable per position. It also means the phones inherit the comms cabinet's UPS: put the switch on battery and every handset in the building rides out a power cut, which no amount of desk adapters will do for you.

Key features

• Integrated PoE, IEEE 802.3af — powered from the switch, no mains adapter needed
• 3 lines, up to 6 SIP accounts — several numbers and providers on one handset
• 2.7-inch 132 × 64 backlit graphical LCD — room for a full name and number
• Three dual-colour line keys — ringing, active and held lines visible at a glance
• Four programmable XML soft keys — context-sensitive, following the call state
• 5-way audio conferencing — run a multi-party call from the phone itself
• Full HD audio, handset and speaker — wideband speech, not narrowband telephony
• Dual Gigabit Ethernet ports — the PC behind the phone keeps full network speed
• RJ9 headset jack with EHS — Plantronics, Jabra and Sennheiser hook switch support
• Secure boot, dual firmware images, GDMS — safe remote upgrades at estate scale

Works with

• Grandstream GRP2603 — the same phone with a mains adapter instead of PoE
• Grandstream GRP2604P — adds 10 BLF keys for staff who watch colleagues' lines
• Grandstream GRP2602P — the two-line PoE model where budget is tightest
• Grandstream GRP2601P — the entry-level PoE model
• Replacement curly cord — fits the whole GRP range
• Headsets — EHS and USB options for high-volume callers
• PoE injectors and switches — if the desk has no PoE at the other end
• All Grandstream IP phones

Frequently asked questions

Does it come with a power supply?

No — it is powered over Ethernet, which is the difference between this and the plain GRP2603. If the switch port does not supply PoE, add an injector or order the GRP2603 instead.

Six SIP accounts on three keys — how does that work?

All the registered accounts are live at once; the three keys are the call appearances you use to switch between and watch them. Three keys is the practical limit of what most people track without a BLF panel.

Do I need the Gigabit ports?

Only if a computer shares the drop. Voice never needs more than 10/100. But if the desk has a PC behind the phone, a 10/100 phone caps that PC at 100 Mbps — and users notice that far more than they notice the phone.

How is it different from the GRP2604P?

Ten BLF keys. Same three lines, same six accounts, same display, same ports. If someone spends their day transferring calls to named colleagues, the 2604P earns its extra cost; if not, it does not.

How much power does it take from the switch?

It is an 802.3af device, so it sits comfortably in the budget of any modern PoE switch. Count the phones against the switch's total watts, not against its port count.

Can I roll out a large batch without touching each phone?

Yes. GDMS and TR-069 with encrypted provisioning and secure boot mean phones can be configured centrally and shipped to site sealed — which is the reason the GRP range exists.

Rolling out desk phones? Call 0333 242 1314 or email sales@clisecure.com and we will check the model, the PoE budget and the provisioning before you order.