License requirements

Can anyone confirms about the license requirements for MS Dynamics CRM 2015 on premises with 4 Servers and 50 Professional CAL. For CTI we want to use MSCRM-AddOns CTI adapter? 

I've been provided some details from a vendor and they gave me something like the following.

1. MSCRM 2015 Server CALS around 6,000 USD
2. MSCRM 2015 Professional CALS around 1200 USD
3. MSCRM 2015 Business Ready Enhancement Plan for 1 Year (They say it's SA) around 39,000 USD

4. Microsoft Windows Server External Connector LicSAPk OLP NL Gov Qlfd for around 2,500 USD per server

5. MSCRM-AddOns CTI Server for around 650 USD Per Server
6. MSCRM-AddOns CTI Client around 100 USD Per Client
7. MSCRM 2015 CTI Implementation Service around 20,000 USD

What I am not sure about is the following:

-: MSCRM 2015 Business Ready Enhancement Plan for 1 Year (They say it's SA) around 39,000 USD
-: Microsoft Windows Server External Connector LicSAPk OLP NL Gov Qlfd for around 2,500 USD per server
-: MSCRM 2015 CTI Implementation Service around 20,000 USD

Do we need these licenses and if yes what is the purpose of each. Does anyone has any experience in this and can anyone guide me about this especially the last 3 items mentioned above?? What type of licenses we actually need here.

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Ali