Tuesday, October 9, 2012

VGW - MGCP the Easy Way

     Media Gateway Control Protocol (MGCP) is a is a plain-text (sent over UDP on port 2427) protocol used by call-control devices (like Communications Manager), known as media gateway controllers (MGCs) or call agents (CAs), to take control of a specific port on a gateway. Cisco Communications Manager knows and controls the state of each individual port on the gateway.

     If you want the fastest and automated way of configuration an MGCP gateway, you can utilize the "ccm-manager config server" CLI command. Having this automated MGCP configuration does not allow for partial/fractional T1 PRI's, but what you can do is enable the automation, modify the T1 manually, and disable the automation after all of the commands have been populated. Here's the steps in setting up an MGCP gateway:

  1. On the gateway, set the "ip domain name" and "hostname"(eg. BR1.company.com)
    1. This provides the full domain name which MGCP utilizes to register the gateway
  2. Configure the gateway on Cisco Communications Manager
    1.  CM Administration > Device > Gateway
    2. Add New
    3. Select specific Gateway Type (eg. Cisco 3945)
    4. Select MGCP as the protocol
    5. Set the full domain name of the router and CUCM Group
    6. Set the appropriate modules 
    7. Configure each of the endpoints/circuits
  3. From the Gateway's CLI configure MGCP
    1. mgcp bind control source-interface <voice interface or loopback>
    2. mgcp bind media source-interface <voice interface or loopback>
    3. ccm-manager config server <CUCM IP Address Primary> <CUCM IP Address Secondary>
    4. ccm-manager config
    5. ccm-manager mgcp

 MGCP Messages:
Command
Message Name
Sent By
Description
AUEP
AuditEndpoint
CallManager
Determines the status of a given endpoint.
AUCX
AuditConnection
CallManager
Retrieves all the parameters associated with a connection.
CRCX
CreateConnection
CallManager
Creates a connection between two endpoints.
DLCX
DeleteConnection
Both
From CallManager: Terminates a current connection.
From Gateway: Indicates that a connection can no longer be sustained.
MDCX
ModifyConnection
CallManager
Changes the parameters associated with an established connection.
RQNT
NotificationRequest
CallManager
Instructs the gateway to watch for special events such as hooks or DTMF tones. It is also used to instruct the gateway to provide a signal to the endpoint (for example, dial tone and busy tone).
NTFY
Notify
Gateway
Informs the Cisco CallManager when requested events occur.
RSIP
RestartInProgress
Gateway
Informs the Cisco CallManager that an endpoint or group of endpoints are taken out or placed back into service.









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Saturday, October 6, 2012

CUCM - Service Parameters

     Service Parameters are global settings on multiple CUCM services (CallManager, IP Voice Media, Extension Mobility, etc.) that may apply to all servers (clusterwide parameters) or to only specific nodes (server parameters).

     Keep in mind that for Service Parameters, there is an "Advanced" button at the top of the page which presents additional Service Parameter options!


Service Parameters

Parameter Name
Suggested Value
Parameter Value
Description
CDR Enabled Flag
True
False
Enables Call Detail Records
CDR Log Calls with Zero Duration Flag
False
False
Enables CDR for calls that never connected or that lasted for < 1 sec
Station KeepAlive Interval
30
30
Interval between KeepAlives from IP phones to CUCM
Station and Backup Server KeepAlive Interval
60
60
KeepAlive interval between phone and secondary CUCM
T301 Timer (Alerting Timeout)
180000
180000
How long CUCM waits to receive the Alerting message
T302 Timer (Interdigit Timeout)
10000
15000
Timer after each digit is pressed before pushing the call through
Strip + on Outbound Calls
False
False
CUCM strip + on outbound for MGCP GWs and SIP Trunks. H.323 ALWAYS strips the + sign.
Built-in Bridge Enable
On
Off
Enables builtin bridge to save on conferencing resources. G.711 supported only.
Device Mobility Mode
On
Off
Allows roaming phones to dynamically associate with the local device pool
Display Device Mobility Location During Phone Registration
True
True
Displays the Device Mobility location when booting up
Off-hook to First Digit Timer
15000
15000
Time CUCM waits for the first digit to be dialed
Privacy Setting
True
True
Enables (True) or disables (False) the Privacy feature
Allow Peer to Preserve H.323 Calls
True
False
Allows H.323 GW to preserve an active call during a loss of connection to CUCM
SIP Min-SE Value
1800
1800
Minimum Session Expiration timer for SIP
SIP Session Expires Timer
1800
1800
Interval between session refresh requests
Call Park Display Timer
15
10
Time that Call Park number is displayed
Call Park Reversion Timer
60
60
Call reverts back to original phone if not answered
Party Entrance Tone
False
True
Determines if a tone will play when a party joins or exits a call with more than two parties (barge, cbarge, conference, join, meetme)
Block Offnet to Offnet Transfer
False
False
Blocks the ability to transfer an offnet call to another offnet number
Suppress MOH to Conference Bridge
True
True
Don’t play MOH on conference bridges
Drop Ad Hoc Conference
Never
Never
Ad Hoc Conference bridges stay up as long as two users are on the conference
Maximum Ad Hoc Conference
16
4
Maximum Ad Hoc Conference Participants
Maximum MeetMe Conference Unicast
16
4
Maximum MeetMe Conference Participants
Advanced Ad Hoc Conference Enabled
True
False
Conference Chaining and control Enabled
Forward Maximum Hop Count
8
12
Maximum times a single call can be forwarded or diverted. For Q.SIG calls, the maximum value is 15.
Forward No Answer Timer
16
12
The Global FNA timer setting
Max Forward Hops to DN
8
12
Max number of forwards allowed for a DN. Prevents call routing loops within CUCM
G.722 Codec Enabled
Enabled
Enabled
Enabled G.722 advertisement
Automated Alternate Routing Enable
False
False
Enables CAC Automated Alternate Routing
Single Button Barge/CBarge Policy
CBarge
Off
Sets the Single Button Barge feature to use barge, CBarge or disable
Allow Barging When Ringing
False
False
Allows users to barge before the phone is answered
Stop Routing on Out of Bandwidth Flag
False
False
Call routing behavior for calls through trunks when not enough bandwidth is available. Used for subsequent route lists and AAR/Locations.









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