VoIP with AI

Decode pcap and make a MSC with AI

What's better than creating an easy Message Sequence Chart (MSC) from a PCAP trace? Doing that and analyzing it with AI (Artificial Intelligence)! You can try it too! Simply visit the pcap2msc page, drag and drop your PCAP file, and let the magic happen. Once the MSC is generated, click the AI button to start the AI-powered analysis. Simpel VoIP call with SIP proxy.

Scrol down to see the IA part for this msc.

Summary of the Message Flow

1. Initial INVITE Request: The flow starts with AA sending an INVITE request to AB (IP: 172.16.98.180) for the user 2301, using the SIP protocol.
2. 401 Unauthorized Response: AB responds with a 401 Unauthorized message, prompting AA to send an ACK.
3. Second INVITE: After the ACK, AA sends another INVITE request, which is acknowledged by AB with a 100 Trying status.
4. INVITE to AC: AB then forwards the INVITE to AC (IP: 172.16.98.181).
5. Multiple Status Responses: AC responds with 100 Trying and later with 200 OK. AB then sends ACKs back to both AC and eventually returns a 200 OK to AA.
6. RTP Stream Initialization: An RTP stream is initiated between AA and AC, but later, a "Port unreachable" message indicates a potential issue with the RTP setup.
7. Termination: The flow ends with AC sending a BYE request to AB, which responds with a 200 OK.

Issues in the Message Flow

1. Duplicate INVITE: The sequence shows AA sending an INVITE twice to AB, which is unnecessary and may confuse the session state.
2. Port Unreachable Error: The acknowledgment of the RTP stream is met with a "Port unreachable" error, indicating a possible misconfiguration or dropped packets in RTP.
3. Inconsistencies in SIP messages: There are multiple references to "FROM" addresses based on changing contexts, which could lead to confusion if not handled properly.

Summary of Protocols Used

1. SIP (Session Initiation Protocol):

   • Relevant RFCs:
     • RFC 3261: SIP: Session Initiation Protocol
     • This protocol is used for initiating, maintaining, and terminating real-time sessions that include voice, video, and messaging applications.

2. RTP (Real-time Transport Protocol):

   • Relevant RFCs:
     • RFC 3550: RTP: A Transport Protocol for Real-Time Applications
     • Used for delivering audio and video over IP networks.

Proposal for Entity Names

Based on their roles and the IP addresses provided, I suggest the following entity names:

• AA: Originating_Phone
• AB: SIP_Proxy_Server
• AC: Receiving_Phone

These names clarify the function and context of each entity within the message flow, making it easier to understand the communication process.

In conclusion, while the message flow follows the basic operational procedures of SIP and RTP, there are areas that require attention, particularly around duplicated messages and the disconnect in RTP handling, which should be addressed to ensure efficient communication.