The Polycom SoundPoint IP 601 Expansion Modules (sidecars) act merely as "overflow" for contacts which won't fit into the phone's own contact/line monitoring buttons to the left of the LCD display. In other words, you can't put contacts into the sidecar without filling up the phone's buttons first. Each expansion module allows an additional 6 extension registrations and one phone can have up to 3 sidecars attached, for a grand total of 24 registered extensions.

The sidecars can see the status of other extensions if buddy watching for the contact is enabled. To enable this, the <bw> tag is is set to 1 in the contact list XML file, and enable the presence feature. To enable the presence feature, set the feature.1.enabled attribute to "1" in the feature tag in the sip.cfg file (or the override file). At least as early as the Polycom SIP 3.0 software, you can also set "Buddy Watch" from the phone's directory edit function.

Plain Asterisk installations may need special configuration in the form of enabling hints for each extension to be monitored, but Trixbox and FreePBX appears to already enable this for extensions.

Where to Buy

• 8774e4VoIP.com - Polycom 601/650 EM - Polycom Certified Vendor
• 888VoipStore.com - Best Prices and Support on Polycom IP601-Side Car. Call for reseller pricing or global shipping. 888-VOIPSTORE.
• Shark Distribution Polycom distributor - Switzerland
• TheTelecomSpot.com - Expert Advice, Low Prices and Free Shipping on Orders Over $99 - VoIP Phones > Polycom Phones > Polycom 601 Expansion - Call 1-866-369-3394
• Polycom Soundpoint IP 601 Expansion Module at Telephony Depot: A premier retailer in the VoIP industry's online marketplace.
• VoIPandGo Cheap Prices! Great Service! Quick delivery by UPS. Reseller Prices Available!!
• VoIPGizmos.ca - Polycom Soundpoint IP 601 - Canada
• Voiplink - Expansion Module for Polycom 601 & 650 IP Phones Your one stop shop for VoIP Equipment! 866-987-8647
• Polycom IP 601 in stock at VoIP Supply. View the entire line of Polycom IP Phones
• Polycom IP Phones - at IPChitChat - Polycom Phones - Polycom IP601 Expansion Module