Customer Resource Management (CRM) is either in house developed or off the shelf suite for customer/client management. You can generate invoices, quotes and pay orders on the fly for any customer. You can keep track of your marketing and sales campaigns. Also you can keep track of your internal and external trouble tickets. However we also offer a separate ticketing system. OTRS for companies who heavily rely on that.
We offer deployment, configuration, support and integration with vicidial for two of the leading CRMs vtiger and sugarcrm. Both are awesome products however if we have to make a statement then go for vtiger unless you are a big team. Both the software have open-source versions which make them free of cost.
This offers just a button for TSR/CSR to open CRM portal from their agent screen on vicidial. CRM opens either in a new tab of web browser or in an I-frame of current tab.
For simplicity you can create same user logins and password on both vicidial and CRM. However there would be no data sharing between the two on database level. Less convenient but cost you nothing on integration part.
In this approach vicidial and CRM share same data. So there is single point of controlling the modifications. A user created in vicidial would appear in CRM also. Same can be achieved for leads and campaigns. We assess the levels at which you want this integration and quote accordingly.