Telephone Systems for ISDN Lines - ISDN2e Lines provide additional features over standard analogue lines.  The main reason for using ISDN lines is the DDI feature (Direct Dial In).  The DDI feature means you can have a block of 20 or 30 numbers over 2, 4, 6 or 8 channels so each telephone extension can have it's own thelephone number so calls can be made directly to that extension, bypassing the reception or general ring group / hunt group.

Siemens BizIP - VoIP PBX for up to 16 extensions - self install small business phone system BizIP AD20 Access Device for the Siemens HiPath BizIP PBX Solution. The BizIP AD20 provides 2 x ISDN2e Line Ports and 2 x FXS analogue extension ports. £275.00 ex. VAT More info Buy

Siemens Optipoint 410 e Standard VoIP Phone for the Siemens BizIP VOIP Phone System The Siemens Optipoint 410e standard phone for BizIP £165.00 ex. VAT More info Buy

Siemens Optipoint 410a Comfort VoIP Phone for the Siemens BizIP VOIP Phone System VOIP Phone for the BizIP - Siemens Optipoint 410 a Comfort IP Phone £265.00 ex. VAT More info Buy