Thursday, February 28, 2013

Understanding the Difference Between Restart and Reset

You can reset or restart a phone in Cisco CallManager Administration. What is the
difference between resetting and restarting?


Basically, the reset command causes the IP phone to completely power-cycle and begin again as if it had just been plugged in.


The restart command tells the IP phone to unregister and then reregister with CallManager.

Tuesday, June 12, 2012

SRST testing

Test the SRST configuration: 

## Take down the WAN interface or add a static route to null 0 for any ip packets coming from Unified CallManager ## 

ip route null 0

Tuesday, April 17, 2012

Loop start


When loop start signaling is used, a gateway's FXO interface looks like a phone to
the switch (PBX, PSTN, Key-System) it is connecting to. The FXO interface closes the
loop to indicate off-hook, just as an analog phone does when it is physically lifted
off-hook. The switch always provides battery, so there is no disconnect supervision
from the switch side. Because a switch expects a phone user (which an FXO interface
behaves like) to hang up the phone when the call is terminated (on either side), it
also expects the FXO port on the router to hang up. This "human intervention" is not
built into the router. The FXO port expects the switch to tell it when to hang up (or
remove battery to indicate on-hook). Because of this, it cannot be guaranteed that a
near-end or far-end FXO port will disconnect the call after either end of the call has
hung up.

Tuesday, January 10, 2012

Disable toll fraud feature on IOS 15

Router# conf t
Router(conf)# voice service voip
Router(voice-ser-voip)# no ip address trusted authenticate

Thursday, January 5, 2012

Difference between Unicast and Multicast MOH

MOH server is commanded to generate a stream to the IP address of the endpoint receiving the stream. The endpoint is told to listen to the stream, which includes various messages depending on the protocol and the type of endpoint. When the call is to be taken off hold, the MOH server is told to stop streaming, and the held party is connected to the appropriate endpoint.

MOH server is always streaming the multicast stream. As such, CallManager doesn't need to tell the MOH server to do anything. The endpoint is simply told to listen to the multicast stream.

Wednesday, December 28, 2011

Database replication states

0—This value indicates that replication did not start. Either no subsequent nodes (subscribers) exist, or the Cisco Database Layer Monitor service is not running and has not been running since the subscriber was installed.

1—This value indicates that replicates have been created, but their count is incorrect.

2—This value indicates that replication is good.

3—This value indicates that replication is bad in the cluster.

4—This value indicates that replication setup did not succeed.

Friday, October 28, 2011

Default Dial Peer or dial peer 0

The default dial peer and its call parameters cannot be modified. This dial peer may be a POTS dial peer or a voice-network dial peer, and is always referred to as dial peer 0 or pid:0.

Dial peer 0 (pid:0) has a default configuration that cannot be changed. The default dial peer cannot negotiate non-default capabilities, services, and applications such as:

  • Non-default Voice-Network capabilities, such as DTMF Relay and VAD
  • Direct Inward Dial (DID)
  • (Tool Command Language) TCL Applications

The default dial peer for inbound VoIP peers has the following default configuration:

  • It supports any codec
  • It has VAD enabled
  • It provides no Resource Reservation Protocol (RSVP) support
  • It provides fax-rate voice support

The default dial peer for inbound POTS peers has the following default configuration:

  • It does not support Interactive Voice Response (IVR) applications