where fund pjsip, sip2sip, php-sip

As an AI language model, I don't have access to the funding sources of specific projects. However, here are some general ways that open source projects like PJSIP, SIP2SIP, and PHP-SIP can be funded:

1. Donations: Open source projects often rely on donations from individuals or companies that use or appreciate the software. Some projects have a donation page on their website or accept donations through platforms like Patreon or Open Collective.

2. Grants: Some organizations offer grants or funding to open source projects that align with their mission or goals. For example, the Mozilla Open Source Support (MOSS) program provides funding for open source projects that support the Mozilla mission.

3. Sponsorship: Companies or individuals can sponsor open source projects by providing financial support in exchange for recognition or other benefits. This can include having their logo displayed on the project's website or documentation.

4. Consulting or support services: Some open source projects offer consulting or support services for a fee. This can include custom development or integration services, training, or ongoing support and maintenance.

5. Crowdfunding: Some open source projects have successfully raised funds through crowdfunding platforms like Kickstarter or IndieGoGo. This can be a way to generate interest and support for a project while also raising money.