> Source: [sk178586](https://support.checkpoint.com/results/sk/sk178586)

# sk178586 - VoIP phones do not register to the Call Manager when using the SIP service with a specific inspection handler

| Property | Value |
|----------|-------|
| Solution ID | sk178586 |
| Date Created | 2022-03-30 |
| Last Modified | 2022-04-14 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R81.10 (EOS), R81 (EOS) |
| OS | Gaia |

## Symptoms

- * VoIP phones do not register/unregister from the Call Manager (SIP server, Gatekeeper, and more).

* Rebooting the VoIP phones does not resolve the issue.

* In the properties of the SIP service used in the applicable Access Control rule, a specific value is selected in the "Protocol" field.

* Changing the SIP service properties and selecting "None" in the "Protocol" field resolves this issue.

## Cause

When a VoIP phone tries to register to a Call Manager, the VoIP phone must be configured according to the "rules" of the Call Manager. The VoIP phone cannot get the required rules from the Call Manager.

<br />

## Solution

This solution requires authentication. Please log in to view the full solution.

---

# Agent Instructions

This content is from the Check Point Support Center (https://support.checkpoint.com), the official knowledge base for Check Point cybersecurity products.

## Navigating This Knowledge Base

- **Complete index**: [llms.txt](https://support.checkpoint.com/llms.txt)
- **All SK articles**: [SecureKnowledge Sitemap](https://support.checkpoint.com/sitemaps/secureknowledge-sitemap-index.xml)
- **SK article URL pattern**: `https://support.checkpoint.com/results/sk/{skId}`
- **Markdown responses**: AI bot User-Agents automatically receive `text/markdown` content