Voipfone SIP Expert for Caller ID Java Code

I'm in urgent need of an individual adept in Voipfone SIP services and Java. Unfortunately, I don't have access to the Voipfone documentation and API credentials. Hence, a freelancer who is already versed in said provider would be preferred. The ultimate goal is to create a compact Java project that fetches caller ID information from Voipfone's SIP services.

Key responsibilities:
- Creating Java code for Voipfone SIP caller ID queries
- Overcoming lack of direct API access

Desired skills and experience:
- Expertise in working with Voipfone services
- Proficient in SIP technology
- Strong knowledge in Java
- Ability to work around API limitations effectively

The project time frame is ASAP. So a freelancer capable of prompt and efficient service delivery will be highly appreciated. Please bid with confidence if you have the necessary skills and experience.