Sounds like you just need to use an old school telephone feature called LINK (Northern Telecom Canadian name) or Flash in American terminology.
Alright more thank likely if you have analog/POTS VOIP lines from Comcast/ATT/Vonage you can simply do this.
When first call comes in, talk to party, then to Transfer:
Press Feature 71
1-Then wait for dial tone, then dial number of party you want to transfer to
2-Once Ringing begins, Press RLS to release the Line
3-The Call you transferred will now be ringing on the external party
This is called a blind transfer
If you want to perform a consulted transfer and tell the person who is accepting the transferred call, who is calling them,
Press Feature 71
1-Then wait for dial tone, then dial number of party you want to transfer to
2-Once Ringing begins, wait for third party to answer and tell them you are transferring a call
3-Press RLS you'll be released and the two parties will be connected
4-The Call you transferred will now be ringing on the external party
So in other words you can have a 3 Way call as well if you want.
Additionally you can program a spare autodial button on the Norstar phone to say DIR Transfer etc....
1-Press Feature *3
2-Press the button you want to program
3-Once an "F" appears on the display, Enter Feature 71 and press OK or press RLS
4-button is now programmed with the LINK Feature 71 button
If you want to program the external number you are constantly transferring a call to:
1-Press Feature *1
2-Press the button you want to program the external number on
3-Press 1-area code-phone number
4-Press RLS or OK and the button is now programmed
DO NOT CONFUSE THE TRANSFER FEATURE 70 OR THE TRANSFER BUTTON ON THE SOFT KEYS ON THE TELEPHONE WITH EXTERNAL TRANSFERS. THIS TRANSFER BUTTON IS FOR INTERNAL CALLS ONLY, SAY YOU WANT TO TRANSFER A CALL FROM EXT. 222 TO EXT 225. THIS HAS NOTHING TO DO WITH EXTERNAL TRANSFERRING.
The reason why? The transfer you are trying to do is using Comcast's phone switch to the do the transferring. By Pressing Feature 71, you are initiating what is called a "Hookflash" which tells the Comcast phone system you want to transfer a call or conference a call. Think of it as the old school call waiting when you pressed Flash to link between two calls. Northern Telecom always named this button Link....
Joseph Sus Jr. Nortel Enthusiast