sip-ua
sip-server ipv4:10.4.1.100:5060
dial-peer voice 1000 voip
session target sip-server
…

The sip-server command on the dial-peer tells the Cisco IOS gateway to use the globally defined
sip-server that is configured under the sip-ua settings. In order to configure multiple SIP Proxies for redundancy, you can change the IP address to a DNS SRV record, as shown in the following example. The DNS SRV record allows a single DNS name to be mapped to multiple servers.

sip-ua
sip-server dns:cvp.cisco.com
dial-peer voice 1000 voip
session target sip-server
…

Alternatively, you can configure multiple dial-peers to point directly at multiple SIP Proxy servers, as shown in the following example. This configuration allows you to specify IP addresses instead of relyingon DNS.

dial-peer voice 1000 voip
session target ipv4:10.4.1.100
preference 1
…
dial-peer voice 1000 voip
session target ipv4:10.4.1.101
preference 1
…

In the preceding examples, the calls are sent to the SIP Proxy server for dial plan resolution and callrouting. If there are multiple Unified CVP Call Servers, the SIP Proxy server would be configured with multiple routes for load balancing and redundancy.

DNS SRV records allow an administrator to configure redundancy and load balancing with finer
granularity than with DNS round-robin redundancy and load balancing. A DNS SRV record allows you to define which hosts should be used for a particular service (the service in this case is SIP), and it allowsyou to define the load-balancing characteristics among those hosts. In the following example, the
redundancy provided by the three dial-peers configured above is replaced with a single dial-peer using a DNS SRV record. Note that a DNS server is required in order to do the DNS lookups.

ip name-server 10.4.33.200
dial-peer voice 1000 voip
session target dns:cvp.cisco.com

With Cisco IOS gateways, it is possible to define DNS SRV records statically, similar to static host records. This capability allows you to simplify dial-peer configuration while also providing DNS SRV load balancing and redundancy. The downside of this method is that, if the SRV record needs to be changed, it must be changed on each gateway instead of on a centralized DNS server. The following example shows the configuration of static SRV records for SIP services handled by cvp.cisco.com, and the SIP SRV records for cvp.cisco.com are configured to load-balance across three servers.

ip host cvp4cc2.cisco.com 10.4.33.132
ip host cvp4cc3.cisco.com 10.4.33.133
ip host cvp4cc1.cisco.com 10.4.33.131
(SRV records for SIP/TCP)
ip host _sip._tcp.cvp.cisco.com srv 1 50 5060 cvp4cc3.cisco.com
ip host _sip._tcp.cvp.cisco.com srv 1 50 5060 cvp4cc2.cisco.com
ip host _sip._tcp.cvp.cisco.com srv 1 50 5060 cvp4cc1.cisco.com
(SRV records for SIP/UDP)
ip host _sip._udp.cvp.cisco.com srv 1 50 5060 cvp4cc3.cisco.com
ip host _sip._udp.cvp.cisco.com srv 1 50 5060 cvp4cc2.cisco.com
ip host _sip._udp.cvp.cisco.com srv 1 50 5060 cvp4cc1.cisco.com

Cisco highly recommends the use of UDP instead of TCP for SIP signaling. TCP stack timeout delays can cause significant delays to the caller during failures.

When the phone receiving MOH is part of a system that uses a G.729 codec, transcoding is required between G.711 and G.729. The G.711 MOH must be translated to G.729.

Note: Because of compression, MOH using G.729 is of significantly lower fidelity than MOH using G.711.

Below are some MOH resources

• Flash Memory: MOH can be played from local stored files in flash memory without the requirement of external source
• Live Feed: The multicast audio stream has minimal delay for local IP phones. The MOH stream for PSTN callers is delayed by a few seconds. If the live feed audio input fails, callers on hold hear silence.
• Live Feed and Flash Memory: This is the preferred method if you want to use Live Feed, so that if Live Feed fails then users still have MOH from local flash memory

Below is very basic configuration for MOH

CME(config-telephony)# moh {filename.wav | filename.au}
CME(config-telephony)# multicast moh 239.1.1.30 port 2000

Cisco Unified CME 8.0 MOH enhancement allows you to create MOH groups and assign ephone extension numbers to these MOH groups to receive different media streams. Callers to the extension numbers configured under the MOH groups can listen to different MOH media streams when they are placed on hold. Following precedence rules are applicable when an ephone caller is placed on hold:

• MOH group defined for internal calls takes highest precedence
• MOH group defined in ephone-dn takes the second highest precedence
• MOH group defined in ephone-dn-template takes precedence if MOH group is not defined in ephone-dn or internal call.
• Extension numbers defined in a MOH-group has the least precedence
• Phones not associated with any MOH groups default to the MOH parameters defined in the moh command under telephony-service configuration mode.

router# show voice moh-group
telephony-service
  moh alaska.wav
  Moh multicast 239.1.1.1 port 16384 route 10.1.4.31 10.1.1.2

voice moh-group 1
  description this moh group is for sales
  moh flash:/hello.au
  multicast moh 239.1.1.1 port 16386 route 239.1.1.3 239.1.1.3
  extension-range 1000 to 1999
  extension-range 2000 to 2999
  extension-range 3000 to 3999
  extension-range A1000 to A1999

voice moh-group 2
  description (not configured)
  moh flash1:/minuet.au
  multicast moh 239.23.4.10 port 2000
  extension-range 7000 to 7999

The Automatic Line Selection feature allows you to specify, on a per-phone basis, the line that is selected when you pick up a phone handset. Any of the following behaviors can be assigned on a per-phone basis:

• Automatic line selection Picking up the handset answers the first ringing line or, if no line is ringing, selects the first idle line. Use the auto-line command with no keyword or argument. This is the default.
• Manual line selection (no automatic line selection) Pressing the Answer soft key answers the first ringing line, and pressing a line button selects a line for an outgoing call. Picking up the handset does not answer calls or provide dial tone.
• Use the no auto-line command. Automatic line selection for incoming calls only. Picking up the handset answers the first ringing line, but if no line is ringing, it does not select an idle line for an outgoing call. Pressing a line button selects a line for an outgoing call.
• Use the auto-line incoming command. Automatic line selection for outgoing calls only. Picking up the handset for an outgoing call selects the line associated with the button-number argument. If a button number is specified and the line associated with that button is unavailable (because it is a shared line in use on another phone), no dial tone is heard when the handset is lifted. You must press an available line button to make an outgoing call. Incoming calls must be answered by pressing the Answer soft key or pressing a ringing line button.
• Use the auto-line command with the button-number argument. Automatic line selection for incoming and outgoing calls. Pressing the Answer soft key or picking up the handset answers an incoming call on the line associated with the specified button. Picking up the handset for outgoing calls selects the line associated with the specified button.
• Use the auto-line command with the button-number argument and answer-incoming keyword.

ephone 5
  auto-line 5 answer-incoming

After-hours call blocking has three major steps of configuration:

1. Define days and/or hours of the day that your company considers off-hours.
2. Specify patterns that you would like to block during the times specified in Step 1.
3. Create exemptions to the policy, if needed.

CME(config-telephony)# after-hours date dec 25 00:00 00:00
CME(config-telephony)# after-hours day fri 17:00 8:00
CME(config-telephony)# after-hours day thu 17:00 8:00
CME(config-telephony)# after-hours day wed 17:00 8:00
CME(config-telephony)# after-hours day tue 17:00 8:00
CME(config-telephony)# after-hours day mon 17:00 8:00
CME(config)# telephony-service

CME(config-telephony)# after-hours block pattern 1 91..........
CME(config-telephony)# after-hours block pattern 2 9011T
CME(config-telephony)# exit

CME(config)#ephone 1
CME(config-ephone)# after-hours exempt

You can use alternate way to exempt phone by using PIN, because users have to give PIN to dial blocked patterns during after-hours. User can use Login (This SoftKey will be active after configure login under telephony-service) soft key with key configured to avail dialing facility during off-hours

CME(config-telephony)# login timeout 120 clear 23:00
CME(config-telephony)# exit

CME(config)#ephone 2
CME(config-ephone)# pin 1234
CME(config-ephone)# restart

CME(config)#ephone-dn 80
CME(config-ephone-dn)#number 5555
CME(config-ephone-dn)#paging
CME(config-ephone-dn)#exit
CME(config)#ephone 1
CME(config-ephone)#paging-dn 80
CME(config-ephone)#exit
CME(config)#ephone 2
CME(config-ephone)#paging-dn 80
CME(config-ephone)#exit

You can use nested configuration to use multiple paging group in a single group

CME(config)#ephone-dn 81
CME(config-ephone-dn)#number 6666
CME(config-ephone-dn)#paging
CME(config-ephone-dn)#paging group 80,81
CME(config-ephone)#exit
CME(config)#ephone 2
CME(config-ephone)#paging-dn 80
CME(config-ephone)#exit

For multicast paging use the following in paging group configuration mode

CME(config-ephone-dn)#paging ip A.B.C.D port 2000

To configure intercom functionality, you must configure two new ephone-dns, one for each side of the intercom connection. These intercom lines should be assigned a number, just like any other ephone-dn. However, in order to prevent others from accidentally (or purposely) dialing the intercom and ending up on muted speakerphone for a random IP phone, the number should be something users cannot dial from other IP phones.

CME(config)# ephone-dn 11

CME(config-ephone-dn)# number A100

CME(config-ephone-dn)# intercom A101 label “Manager”

CME(config-ephone-dn)# exit

CME(config)# ephone-dn 22

CME(config-ephone-dn)# number A101

CME(config-ephone-dn)# intercom A100 label “Assistant”

CME(config-ephone-dn)# exit

CME(config)# ephone 2

CME(config-ephone)# button 2:11

CME(config-ephone)# restart

CME(config-ephone)# exit

CME(config)# ephone 2

CME(config-ephone)# button 2:22

CME(config-ephone)# restart

Notice the number assigned to ephone-dn 11 is A100. You cannot dial this number from a Cisco IP phone keypad, but you can assign it to a speed-dial button. The intercom command acts like a speed-dial button on the ephone-dn. In the case of ephone-dn 11, the command intercom A101 dials the number A101, which is assigned to ephone-dn 22. Because ephone-dn 22 is also configured with the intercom command, it auto-answers the incoming call on muted speakerphone. The label syntax allows you to assign a logical name to the speed-dial; otherwise, the A101 or A100 label will show up next to the line button on the phone. There are three other arguments you can use with the intercom command to tune the functionality:

barge-in: Automatically places an existing call on hold and causes the intercom to immediately answer.

no-auto-answer: Causes the phone to ring rather than auto-answer on speakerphone

no-mute: Causes the intercom to answer with un-muted speakerphone rather than muted. While this is beneficial to allow immediate two-way conversation, you also run the risk of one side barging into existing conversations or background noise.

Configuring Call Pickup is very simple, just divide phones into groups and then assign each ephone-dn to specific pickup group

CME(config)# ephone-dn 1
CME(config-ephone-dn)# pickup-group 5509
CME(config-ephone-dn)# ephone-dn 2
CME(config-ephone-dn)# pickup-group 5509
CME(config-ephone-dn)# ephone-dn 3
CME(config-ephone-dn)# pickup-group 5509
CME(config-ephone-dn)# ephone-dn 4
CME(config-ephone-dn)# pickup-group 5510
CME(config-ephone-dn)# ephone-dn 5
CME(config-ephone-dn)# pickup-group 5510
CME(config-ephone-dn)# ephone-dn 6
CME(config-ephone-dn)# pickup-group 5510

If any extension in group is ringing then other can pick up that call by simply dialing pickup-group number after pressing GPickUp or PickUp. Some consideration

• If multiple phones are ringing then CME will offer oldest call
• In case of single pickup group, user don’t have to dial pickup-group number

• Call park is enhanced feature which allow you to pick up call put on hold from any phone across the organization.
• Call park “parks” the caller on hold at an extension rather than on a specific line.
• Any IP phone that is able to dial the park extension number can retrieve the call.
• The call park system works by finding free ephone-dns in the Cisco Unified CME configuration that you have not assigned to an IP phone and have specifically designated as a call park slot.
• You can either allow CME to park calls randomly at the first available ephone-dn or allow users to choose the extension where the call is parked. Each of these scenarios fits different environments.
• Calls being parked at random extensions might work well for a warehouse environment with a voice paging system. When an employee has a call, the receptionist could announce, “Larry, you have a call on 5913″ over the loudspeaker, at which point Larry could go to a phone and dial the extension to pick up the call on hold.
• Choosing extensions would work well for an electronics superstore in which each department responded to a known extension number. For example, software could be extension 301, cameras could be extension 302, and so on. The receptionist can then park multiple calls on a single call park number (this would require multiple ephone-dns assigned the same extension). As the specific department retrieves the calls, CME would distribute them in the order in which they were parked. The call parked longest would be answered first. You can configure call park simply by adding an ephone-dn designated for call park purposes.

This can be implemented in very simple way using command park-slot in ephone-dn configuration mode

ephone-dn 5
  number 3001
  park-slot

Park-slot has the following options

reserved-for <DN>

timeout <seconds>

limit <count>

notify <dn>

only

recall

transfer <dn>

alternate <dn>

retry <seconds>

CME(config)# ephone-dn 50
CME(config-ephone-dn)# number 3001
CME(config-ephone-dn)# name Maintenance
CME(config-ephone-dn)# park-slot
CME(config-ephone-dn)# exit

CME(config)# ephone-dn 51
CME(config-ephone-dn)# number 3002
CME(config-ephone-dn)# name Sales
CME(config-ephone-dn)# park-slot ?

reserved-for reserves this park slot for the exclusive use of the phone with the extension indicated by the transfer target extension number and  timeout set call park timeout.

CME(config-ephone-dn)# park-slot timeout ?

<0-65535> Specify the park timeout (seconds) before the call is returned to the number it was parked from.

CME(config-ephone-dn)# park-slot timeout 60 ?

Limit Set call park timeout count limit

CME(config-ephone-dn)# park-slot timeout 60 limit ?

<1-65535> Specify the number of park timeout cycles before the call is disconnected

CME(config-ephone-dn)# park-slot timeout 60 limit 10 ?
notify    Define additional extension number to notify for park timeout
recall    recall transfer back to originator phone after timeout
transfer  Transfer to originator or specified destination after timeout limit
          exceeded

Notify Define additional extension number to notify for park timeout recall recall transfer back to originator phone after timeout transfer, transfer to originator or specified destination after timeout limit exceeded

CME(config-ephone-dn)# park-slot timeout 60 limit 10 recall ?
alternate  Transfer to alternate target if original target is busy
retry      Set recall/transfer retry interval if target is in use

Alternate transfer to alternate target if original target is busy retry Set recall/transfer retry interval if target is in use

CME(config-ephone-dn)# park-slot timeout 60 limit 10 recall alternate 1006 retry 10 limit 2

• User Prospective
• System Prospective

User can transfer call using soft key on the phone which can be consulted or blind transfer according to the system configuration. You can configure call transfer feature on the system which give you following options

• full-blind: Perform call transfers without consultation using H.450.2 or SIP REFER standard methods
• full-consult: Perform H.450.2/SIP call transfers with consultation using second phone line if available, fallback to full-blind if second line unavailable. This is the recommended mode for most systems. See also ‘supplementary-service’ commands under ‘voice service voip’ and dial-peer.
• local-consult: Perform call transfers with local consultation using second phone line if available, fallback to blind for non-local consultation/transfer target. Uses Cisco proprietary method.

The following commands required to configure call transfer

telephony-service
  transfer-system {full-blind|full-consult|local-consult}
  transfer-pattern . . . .

Call transfer-pattern command will add some security against toll fraud.

ephone-dn 4 dual-line
  number 1001
  name Shafqut Hamid
  call-forward busy 1007
  call-forward noan 1007 timeout 20                                    
ephone-dn 5 dual-line
  number 1007
  name Shamid
  call-forward busy 1001
  call-forward noan 1001 timeout 20   

There’s an issue with this configuration, because it potentially creates an infinite forwarding loop. You can limit the number of times the call forwarding loop is traversed by setting the max-redirect command under telephony-services. The max-redirect command has a range of 5 to 20 and a default value of five. This is a global command and limits call forwarding system-wide.

The other thing which you should consider while allowing call forward, is to define call-forward pattern which will restrict the user to enable forwarding to certain numbers not any number. You can also use digit manipulation while forwarding calls

telephony-service
  max-redirect 5
  call-forward pattern . . . .

The other way to restrict users to a specific length of call forwarding number from the phone is using call-forward max-length command under ephone-dn. If you will set this parameter to “0” then call forwarding feature will be disabled and soft key on the phone will be grayed out.

ephone-dn 5 dual-line
  number 1007
  name Shafqut Hamid
  call-forward max-length 4
  call-forward busy 1001
  call-forward noan 1001 timeout 20