The IP Phone 1535 videophone uses RFC 3261 compliant Session Initiation Protocol (SIP) to establish both voice and video calls.

Nortel IP Phone 1535 Data Sheet
OVERVIEW
Connected to your local area network (LAN) through an Ethernet connection or by 802.11b/g wireless (WiFi) connection, the IP Phone 1535 provides extensive telephony services, multimedia tools, full video conversation functionality, an array of ring melodies, and a personalized display. You can also use the IP Phone 1535 to check e-mail, voice mail, or browse the Web. The IP Phone 1535 is designed for enterprises seeking a cost-effective personal video endpoint and is also ideal for teleworking groups and multi-site companies who are seeking increased collaboration between sites. The IP Phone 1535 is supported on Nortel Multimedia Communication Server 5100 and Communication Server 2000.
KEY FEATURES:
Provides many functions that would normally require a traditional PC
Easy-to-use multimedia capabilities including personal video conferencing and audio recording along with still image and video captures which can be stored on the phone
Supports integrated applications including web browsing, POP-3 or IMAP-based email access, calendar with alarms, video supervision and image, sound and video library storage
High-resolution, 16-bit color, Thin Film Transistor (TFT) display delivers superior user experience
Flexible connectivity with both wired Ethernet (10/100) and IEEE 802.11b/g WiFi supported
FEATURES & BENEFITS
The IP Phone 1535 supports the following features:
SIP-based videophone (single user login) with an advanced user interface featuring dedicated video function keys to simplify the interactive experience
Eight dedicated telephony-related icon-labeled keys (Send/Handsfree, Goodbye/Release, Video Start, Video Stop, Record, Video Mode, Favorites, Messages) and two context-sensitive soft-label keys for quick item selection
Enhanced navigation/input options with four-way navigation cluster for menu operations and two key “mouse”click (right/left) for web-browsing
Integrated multimedia capabilities including simple, easy-to-use personal video conferencing with video privacy and variable video screen size options, personal audio recording (up to 20 second recordings), still image captures (high/low resolution with camera timer) and video captures (up to 20 second recordings)
Integrated applications including a web browser, e-mail browser (view inbox/outbox or create/send e-mail messages), calendar with alarms, Video Supervision for remote video monitoring and galleries (image, sound and video libraries)
High-resolution, graphical, fully-backlit, 16-bit color (65, 535 colors) Liquid Crystal Display using Thin Film Transistor (TFT) technology
“T9” (Text on 9 keys) dialpad support for predictive text entry1
Integrated Directory/Phonebook for up to 300 contacts (stored in the local directory/phonebook)
Call history for the last 20 items for Missed, Received and Dialed calls
Customized Personalization Options including ringtone support (select from up to 50 local Polyphonic Ringtones), menu color and background image (for idle screen)
Supports Picture Caller ID2 and enhanced display name support (for Caller ID and Call Logs)
Video standards interoperability support with Video Fast Update (for multi-party video conferencing server environments), H.264 SDP negotiation/ interoperability (RFC3984), and interoperability with leading third party H.263/H.264 SIP video conferencing endpoints and conferencing systems3
Memory Card slots for expandability and data input/storage with Subscriber Identity Module (SIM) Reader Slot (used to copy user directory/ phonebook information from a SIM card) and Secure Digital (SD)/MultiMedia Card (MMC) slot (used for external storage and uploading of images or sounds)
Flexible connectivity options with traditional LAN wired Ethernet (10/100 Base-T Fast Ethernet) or Wireless LAN access with an integrated IEEE 802.11b/g (Wi-Fi) radio
Integrated two-way audio speaker
Menu languages supported include English (US), French (Canadian), Spanish (Latin America), German, Portuguese and Korean. (Ph. II only)