1. Module 6 Enterprise IP telephony
BAI613 Packet Telephony
Module 6
Enterprise IP telephony

2. Overview SW-based, call processing piece of Cisco’s AVVID solution
Architecture for Voice, Video, and Integrated Data
CCM is the call-routing and signaling component

3. AVVID Architecture Client Layer Delivers applications to the user
Applications Layer
Physically independent from call-processing in that they may reside elsewhere in the network
Call-processing Layer
May be physically independent from physical layer in that CCM may process calls for devices off-network
Infrastructure Layer
Has ability to support multiple applications, call-processing units, and client devices

4. CCM Fundamentals

5. Hardware Requirements
Cisco has collaborated with both IBM and HP-Compaq to manufacture the Cisco Media Convergence Servers (MCS) . Now the CCM software can be sold separately without buying the hardware from Cisco
Most are rack-mountable except for the model we use (MCS 7825)
There are currently 4 other models
Windows 2000
800 MHz Intel III processor
512 MB RAM
20 GB Fast ATA Hard Drive
Maximum of 500 IP phones standalone Server
Maximum 2500 IP Phones in a cluster

6. CCM Functions Call processing Signaling Device (phone) management
Dial Plans
Other features
Phone key mappings, etc.
IP phones communicate with CCM via Cisco proprietary “Skinny” protocol
IP phones inter-communicate using RTP

7. W2K Services on Cisco AVVID Telephony Servers
CCM
Provides signaling and media control signaling for up to 2500 devices
Cisco IP Voice Media Streaming Applications
Provides H.323 media termination. Music on Hold, and G.711 media mixing capabilities
Cisco MOH Audio Translator
Converts G.711 music source files to G.729a music source files for providing to G.729a capable devices

8. W2K Services on Cisco AVVID Telephony Servers (cont.)
Cisco RIS Data Collector
Collects serviceability information from all cluster members for improved administrability.
Cisco Telephony Call Dispatcher
Allows users such as switchboard attendants to receive and quickly transfer calls to other users; provides automated routing capabilities
Cisco TFTP
Provides preregistration information to devices, including a list of CCM servers with which the devices are permitted to register, firmware loads, and device configuration files

9. W2K Services on Cisco AVVID Telephony Servers
Database Notification
Change notification server and watchdog process that ensures that all IP telephony applications running on a server are working properly
Publisher Database
Serves as the primary read-write data repository for all IP telephony applications in the cluster. This database replicates updates to all Subscriber databases in the cluster
Subscriber Database
Serves as backup read-only database for IP telephony applications running on the server, should the applications lose connectivity to the Publisher database

10. Client Devices Supported by CCM
Station Devices
Generally IP telephony handsets
May also be H.323 clients such as NetMeeting
May also be IP softphones
Gateway Devices
Provide access from one telephone system to another
CCM to another CCM
CCM to a PBX
CCM to the PSTN
Typically use H.323 or MGCP

11. Client Devices Supported by CCM (cont.)
Media Processing Devices
Transcoding Resources
Perform codec conversions between devices that do not encode voice conversations using a common encoding scheme
Unicast Conferencing Devices
Permit Ad Hoc and Meet-Me conferencing
Media Termination Point (MTP) Resources
Allow users to invoke features such as Hold or Transfer even though one of the endpoints does not support them
Music on Hold (MOH) Resources
Provide users access to music sources when they are placed on hold
Ah-Hoc conferencing
user-controlled teleconference
User 1 calls User 2 and they wish to conference in a third party
Meet-Me conferencing
Using a conference bridge
All users who wish to join a conference call dial into a central number and using usernames and passwords, join the conference call.

12. Understanding how devices use TFTP and DHCP Server
IP Phones need access to a TFTP Server that contains device loads and configuration files
The DHCP Server will automatically direct the devices to the TFTP Server (Option 150 in the DHCP Scope)
If a device has been manually added into the Cisco Call Manager database, the device accesses a configuration file corresponding to its device name.
If auto-registration is enabled in Cisco Call Manager, the phones access a default configuration file from the TFTP server.

13. Connecting to the Call Manager
After obtaining the configuration file from the TFTP server, a device attempts to make a TCP connection to the highest priority Cisco Call Manager in the list specified in the configuration file. If the device was manually added to the database, Cisco Call Manager identifies the device.
If auto-registration is enabled in Cisco Call Manager, phones that were not manually added to the database attempt to auto-register in the Cisco Call Manager database.
Cisco Call Manager informs devices using .cnf format configuration files of their load ID.
Devices using .xml format configuration files receive the load ID in the
configuration file.
If the device load ID differs from the load ID that is currently executing on the device, the device requests the load associated with the new load ID from the TFTP server and resets itself.
Once a telephone is ready to make a call, it will request an available ringer list from the TFTP server. If the telephone user changes the ring type, the TFTP server sends the new ring type.
Reference: Cisco Call Manager System Guide Version 3.2 from

14. AVVID Call Establishment
Step 1: Call Signaling
Using the Skinny protocol, the IP phone sends a request to the CCM to originate a call. Request contains address of destination.
CCM locates called party, sends a new call event to to the called device, and waits for called party to respond with answering event

15. AVVID Call Establishment (cont.)
Step 2: Media Control
As called party answers, CCM determines details of media session to be established.
CCM must ensure that both devices can communicate using a common encoding scheme and CCM must provide IP address and port on which called device has chosen to receive data

16. AVVID Call Establishment (cont.)
Step 3: Media Exchange
Once media session is successfully negotiated, devices communicate through IP network infrastructure using RTP/UDP/IP protocols.

17. Configuring CCM

18. Initial CCM Setup DHCP Services must be running on the PC
Start – Programs – Administrative Tools – Services
Double-click DHCP Server
Change Startup type: to Automatic and click Apply
Click Start and wait until the service has started
Click okay to close window
Under Services window, DHCP Server should now indicate Started under Status and Automatic under Startup Type
Close this window

19. DHCP Setup (cont.) Start – Programs – Administrative Tools – DHCP
Under the Action menu, select Add Server
Click Browse and your server will show up by name
Hi-light your server and click OK
Your server will now show up in the DHCP window
An hour-glass will be apparent to the left of the server IP address. Once this disappears, it will be replace by a green arrow indicating your DHCP server is activated

20. DHCP Setup (cont.)
Hi-light your server, click the Action menu and select New Scope
The Welcome to the New Scope Wizard appears
Click next and then enter a scope name and description (optional) and click next
Define your scope range and click next
Add your exclusions (your server, default gateway, etc.), click Add, and then next
Configure a lease duration or leave at default and click next

21. DHCP Setup (cont.)
Leave the default settings on Configure DHCP Options and click next
Add in the address of Default Gateway if one is present and click next
If there is a DNS server, enter it on this page and click next
Same for WINS server, click next
Activate scope and click next
Click finish to complete the wizard
The new scope now appears in your DHCP window

22. DHCP Setup (cont.)
Option 150 needs to be configured on your DHCP server in order for the phones to locate the TFTP server
The phones download their information via TFTP from CCM
Right-click on you server IP address in the DHCP window and select Set Predefined Options
Click Add and type in Option 150
Enter 150 for Code, IP Address for Data Type and enter a description (IP Phones). Click OK and OK

23. DHCP Setup (cont.)
Expand your scope and right-click on Scope Options - select Configure Options
Scroll down until you see Option 150.
Select it and then enter the IP address of your server in the box that appears and click OK
Option 150 now appears in the details pane of your DHCP window under Scope Options

24. Installing Your IP Phones
Pictured below is a screenshot of the initial screen when opening the CCM application
Start – Programs – Cisco Call Manager
Upon initial installation of your phones in a CCM environment, it is easiest to auto-register your phones
From the menu bar select System – Cisco CallManager
Click on your server name located on the left side of the screen (server can be indicated by name or IP address)

25. Installing Your IP Phones (cont.)
Your server will be listed either by name or IP Address
Default is Server name
Ensure all you new IP phones and the CCM are plugged into the same network segment
Tab down to or select the Staring Directory Number field
Choose a 4-digit number
Tab to the next field entitled Ending Directory Number
Choose a new 4-digit number ensuring enough space for all phones
The “Auto-registration disabled” tab changes from selected to un-selected
All phones will now auto-register with the CCM
Lick the Update tab

26. Installing Your IP Phones (cont.)
Once all the phones have auto-registered and have received all its DHCP information and a directory number, return to this filed and re-select the “Auto-registration disabled” radio button
Leaving this open is a security hole in your network

27. Configuring Additional Phone Features
From the top menu bar select Device – Phone
A screen shot appears entitled “Find and List Phones” with no phones shown.
Click on Find
All phones that were detected by “auto-registration” will be shown
Click on the phone with the lowest DN
Name of phone is its MAC address

28. Configuring Additional Phone Features (cont.)
You will see in screen shot below that Line 2 is not configured
Your job is to configure a DN for Line 2
Click Line 2
This screen shot will appear
In the DN field, add another DN
Click Insert and then click Configure Device
This will return you to “Phone Configuration” page

29. Configuring Additional Phone Features (cont.)
The phone will not have the new DN assigned until you click Reset Phone
Click Restart and watch your phone to see what happens and how long it takes

30. Configuring Additional Phone Features (cont.)
Repeat these steps with your other phones by adding a second DN to each phone but instead of clicking Restart, click Reset
You will notice that Restart is much faster than Reset – 1 second vs. 1 minute

31. Configuring Additional Phone Features (cont.)
Configuring Forward Busy and Forward No Answer
Select Line 1 of each phone
Select Forward Busy and enter in the DN for Line 2 of same phone and click Update
Select Forward No Answer and enter DN for Line 2 of same phone and click Update
Restart the phone and test Line for both instances
Note: Forward No Answer forwards the calls without Line 1 ringing
You can change this timer by clicking Configure Device and scrolling down and enabling Forwarding Delay

32. Configuring Additional Phone Features (cont.)
Testing Hold / Resume
View soft keys immediately below screen
Place call from one phone to another and notice the change in soft keys
Place call on hold by pressing Hold soft key and then off hold by pressing Resume key
Using Transfer function
Place call from one phone to another and use Transfer soft key

33. Configuring Additional Phone Features (cont.)
Configuring Ring Tones
Select Settings key on phone (key indicated by square with check mark)
Either use keypad to choose setting or arrow keys to scroll down to Ring Type
Select the Select soft key and test out each ring type and choose the one you like
When phone is ringing use -+ keys to adjust volume
Select Save soft key to save your choice

34. Configuring Additional Phone Features (cont.)
Changing Button Template
From Menu select Device – Phone Button Template
Select Default 7960 (this is phone model we are using) and click Copy
Change buttons 3 and 4 to Line
Change the template name to BAIST Lab and click insert
Return to Device – Phone – Find and choose any phone
Under Phone Button Template change this to BAIST Lab
Now add new DNs to each of these lines
Click Update

35. Configuring the Voice VLAN
By default, when an IP phone is first configured on a switch, it is part of the VLAN to which the switchport belongs.
You need to configure the switchport to also belong to an auxiliary VLAN for the voice traffic
switch(config-if)#mls qos trust device cisco-phone
switch(config-if)# switchport voice vlan dot1p or
switch(config-if)# switchport voice vlan 15

36. Setting DSCP Value for Voice
In the QoS module, you learned to create class-maps and match these classes to a certain type of traffic
Typically ACLs
Another way is to match IP Precedence as the IP phone provides IP Precedence value to the switchport (IP Prec = 5) is to use Class Maps
Switch(config)# class-map match-all GOLD
Switch(config-cmap)# match ip prec 5
Switch(config)# policy-map INBOUND
Switch(config-pmap)# class GOLD
Switch(config-pmap-c)# set ip dscp 46

37. Setting DSCP Value for Voice (cont.)
There is another way to map the IP Precedence value to DSCP
Enable auto-qos for IP phones on the relevant interfaces
Switch(config)# interface fastethernet interface #
Switch(config-if)# auto qos voip cisco-phone
The switch then enables a trust boundary between switchport and IP phone
The switch uses CDP to detect presence of phone
The switch automatically generates a CoS-to-QoS map where IP Precedence level of 5 is mapped to DSCP value of 46 (Expedited Forwarding)

38. CCM and Voice Gateway
IP Telephony gateways enable CCM to communicate with non-IP devices
Gateway control protocols provide the internal interface between voice gateway and CCM
Inter-cluster trunks will be used to connect remote CCMs across the WAN and will be configured as H.323 gateways
Trunk interfaces specify how gateways interfaces with PSTN or other external devices