Understanding MGCP Packets: A brief overview and example with debugs

Mijanur Rahman's Blog

While studying MGCP protocol messages from debugs my head was spinning like ‘what the c**p message are those!’, had an weird idea to generate the call and capture all MGCP packets and write down explanation of each of the terms. I am weak on the MGCP debugs packets from the beginning of starting voice, now I just wanted to nail it down and wished to learn whole conversations between MGCP GW and the Call Agents. Tough one for me I know but who doesn’t want to learn something new? Took the challenge and I think now it’s quite easy for me. 🙂

Before starting the derivation let’s write down the MGCP Packet verbs and code explanations:

Code Verb
AUCX    AuditConnection.
AUEP    AuditEndpoint.
CRCX    CreateConnection.
DLCX    DeleteConnection.
EPCF    EndpointConfiguration.
MDCX    ModifyConnection.
RQNT    NotificationRequest.
NTFY    Notify.
RSIP    RestartInProgress.

200    The requested transaction was executed normally.
250    The connection was deleted.

View original post 1,404 more words


Cisco CIPC with RDP Session

In order to be able to use CIPC on remote computer through RDP:

We need to change the RDP’s Remote Audio default option to ‘Play on remote computer’.


If we don’t change, CIPC will fail to start and will give sound card error message.

Windows 7 NTP Server enabling

Changing the ‘Enabled’ flag to the value 1 enables the NTP Server.

Change the server type to NTP by specifying ‘NTP’ in the ‘Type’ registry entry.

Set the ‘Announce Flags’ registry entry to 5, to indicate a reliable time source.

Set ‘LocalClockDispersion’ to 0

Enabled Value data type 0

Command prompt: net stop w32time then net start w32time.

Don’t forget to disable Windows firewall or enable the following port to flow through.

NTP (and SNTP) uses UDP port 123.

Note: If you try to telnet this port, you will not be able because it is an UDP port. So, go-ahead and try to Sync…