History Of Cisco Callmanager Express

Published Date: 02 Nov 2017

This report is on Cisco CallManager Express, Cisco`s IOS based Telephony services. It is designed to give you an overview of the Cisco CallManager Express solution, the technologies involved and the benefit of using the Cisco CallManager Express solution in small and medium business.

The CallManager is a call processing system developed by Cisco Systems which is software based. It tracks all active VoIP network components; these include phones, gateways, conference bridges, resources transcoding, and voicemail among others.

The Cisco CallManager Express system IP communications products and applications helps the organizations to communicate more effectively which in turn allows them to streamline businesses, get to the right resource the first time.

Overview

We will first look at the dynamics and trends in the industry, and explain why IP Communications is becoming a compelling solution for small and medium businesses. Next, we will discuss the converged applications which are possible over an integrated voice and data network. We will then discuss the technical aspects of Cisco’s CallManager Express solution, explain some key features and review a few typical deployment scenarios.

The Cisco CME is the leading unified network telephony solution that helps organizations to increase productivity and reduce the costs with maintaining separate voice and data networks. The ability to perform many different tasks and complicated efficiency functionality of the Cisco IP network provides the backbone that allows fast implementation of upcoming software such as desktop Cisco IP Telephony, messaging, video telephony, desktop integration, global software convergence with IP phone displays, and collective IP contact centers. These soft wares enhance productivity and help increase enterprise revenues.

What is Cisco CallManager Express?

CallManager Express is a cost-effective IP Communications solution for small

Businesses or branch offices. It is an optional IOS software license that extends the capabilities of the most popular Cisco Full Service Access Routers to simultaneously manage standard routing, VPN, IOS Firewall, and now local IP Communications.

Call processing is integrated within the IOS software to provide the core set of

Telephony features that customers require for their everyday business needs.

CallManager Express supports up to 120 users making it ideal for small businesses or branch office deployments. An intuitive, easy-to-use Graphical User Interface is included to set-up user preferences and facilitate system administration.

Quality of Service

Voice, as a group of IP network traffic, has hard requirements with regards to packet loss, delay, and the variation in the delay which is also known as jitter. To get to these conditions for voice traffic, the Cisco CME IP Telephony solution has the Quality of Service (QoS) features which includes classification, queuing, shaping the traffic, and Transmission Control Protocol or TCP header compression.

The QoS features of the Cisco CME IP Telephony solution are delivered through the dense management of the IP traffic, queueing, and shaping requirements of the Cisco CME IP network. Main conditions of this network that make QoS for IP telephony include:

•Call admission control

•Compressed RTP (cRTP)

•Enhanced queuing services

•Link efficiency

•Link fragmentation and interleaving (LFI)

•Low-latency queuing (LLQ)

•Traffic marking

•Traffic shaping

Security

The Cisco CME has many security features. But the main one that are considered are discussed below:

• The physical security that restricts any kid of physical access to any important servers and network components.

•Network access security that prevents any kind of hostile attacks or login attacks.

•Security measures that has to be followed on routers that run Cisco CME

•Mechanisms for define for each user their calling privileges.

•Careful network design and management to step up the security of the network.

Network Infrastructure

The network infrastructure has the public switched telephone network (PSTN) gateways that are used, analog phone support which is needed, and digital signal processor (DSP) farms. The infrastructure can have many kind of client types such as phones which are hardware and software and video devices. It also has the interfaces and features that are required to integrate legacy PBX systems, voicemail systems, and the directory systems. Usual products that are needed to build the network include Cisco voice gateways, Cisco IOS software and Catalyst switches, and Cisco routers.

Figure CCME Network InfrastructureC:\Users\Nirmal\Downloads\ccme1.jpg

Network Components

In an CallManager Express-based IP Communications network, IP phones are connected to a voice-enabled Ethernet LAN switch, which is connected to an

CallManager Express-enabled router. The CallManager Express software on the Cisco router manages call processing, call control and feature control. This router also functions as a gateway to connect remote sites over either a private or public network, or to communicate with external callers.

In other words, IP-based Communications uses the same LAN as the data network. The Ethernet switch also provides inline power to the IP Phone. A desktop PC LAN connection can be connected in daisy-chain to the IP phone. In this way, one single cable from the switch takes care of power and network connectivity to the IP phone and the PC next to it, bringing significant cost savings.

The router with CallManager Express functionality acts as one single platform for Integrated Voice and Data. It leverages Cisco’s technology leadership in packet infrastructure and Voice-over-IP, to deliver high quality voice, and allows for simple deployment and management.

Network Services

A network service is hosted on a computer network. These services are also known as service protocol since they help the users the in the network to achieve some functionality. These services are provided by servers that are on a Local area network to ensure user friendly operation and security. There are a lot of network services that are used in a network we will look at some of those services.

Domain Name System (DNS)

DNS makes it possible the tracking of host names to IP addresses that are in a network. DNS server implemented in a network has a database that tracks the hostnames to IP addresses. Individuals on the network can ask the DNS server and get IP addresses for the devices which do not have an IP address in the network, thereby easing communication inbetween network devices.

Being dependent on DNS, however, can be troublesome. If the DNS server is not available and a network device depends on that server which is not online to get a hostname to IP-address mapping, communication will fail. This is why, we do not depend on DNS for communicating between Cisco CME and the IP telephony endpoints.

Dynamic Host Configuration Protocol (DHCP)

Devices on the infrastructure use DHCP to get basic configuration information, including IP address of the devices, subnet mask to be used, default gateway to be used, and TFTP server. The administrative hard work of configuring each host manually with an IP address and other information is made easy by DHCP. DHCP also automatically reconfigures the network when a device in the network has been removed or moved. When a client sends a request to the DHCP it responds by sending the configuration from a DHCP server in the network.

Trivial File Transfer Protocol (TFTP)

Inside a Cisco Unified CME system, endpoints depends on a TFTP based measure to get configuration information. A request is sent by the endpoints which has a name based on its MAC address. The configuration information contains the information of the phone like the version of the software it should be running and other basic information required by the phone.

If the phone gets a configuration file which asks the phone to run a file that is not the one which is currently being used the phone will then request for the new version of the software from the TFTP server. The phone will do this every time it is rebooted or turned on and before registering itself.

Network Time Protocol (NTP)

NTP lets the devices in the network to synchronize their clocks to the time in a network server. NTP is important for making sure that all the devices in the network have the same time. It important to make sure that the devices have the same time when managing or troubleshooting a telephony network since only then the time stamps in all error given and security logs that will be generated, traces in the network, and system reports generated on devices will be the same throughout the network. This synchronization makes it possible for the administrators to create again activities in the network and behaviors of the networks looking at a common timeline.

Standalone Network Infrastructure Overview

Cisco CallManager Express makes it a lot easier to manage a single site. It would require a lot of work to have maintained a standalone office before IP telephony since that office would require an onsite router which will be used only for data services and also needs a separate key system which will be made use for voice services. The router can then be made to provide an integrated and converged voice and data services to the standalone office. Though it has been converged it can be managed just like before by a VAR or SI or by an ISP. The advantages being both the service provider and business saving space, cost and management.

Cisco CME can be implemented in just wiring of a new office making it a lot more cost effective. The phone and computers are Ethernet based so it is enough if the office has Ethernet based wiring. Moreover, it is enough if a desktop has one Ethernet wire and a jack. Computer devices can be inserted into the phone`s back, and the technology virtual LAN makes it possible to get separation virtually which also provides security of voice from data traffic.

XML services which are the Leading edge productivity features, which also improve the customer service applications based on IP, can also be implemented easily over this unified infrastructure.

Figure Standalone Office Network Topologyhttp://www.cisco.com/en/US/i/100001-200000/140001-150000/149001-150000/149941.jpg

Multisite Network Infrastructure Overview

Cisco CME there are less than 200 users (which can allow growth) and with a provisioning model that is centralized it is not required. It starts to make sense to have a centralized Cisco CME based on the following factors.

•The individual business

•Its management style

•How well the QoS is ready for the network between sites

•The cost for the intersite connectivity

•How much each site needs the other one during a normal productive day.

A network which is based on a PSTN network for voice access is actually good for an environment with a network which is based on the loosely operational model and connected with only a less needed data network (which is a bandwidth of less than 64 kbps and also requires no QoS deployment). This network is basically the equal as the standalone model which has be discussed earlier. since the sites got only PSTN calling in look like a standalone form (from a perspective). In comparison, a multisite model that is more closely coupled (with entry to less expensive QoS) of VoIP connected between the sites to get all toll savings and other more advantages.

Figure Multisite Distributed Cisco Unified CME Network Topologyhttp://www.cisco.com/en/US/i/100001-200000/140001-150000/149001-150000/149942.jpg

LAN Infrastructure

LAN design is very important for proper IP telephony implementation on a unified network. Proper LAN wants the following configuration and best practices for providing a highly good network., proper LAN needs implementing end-to-end QoS on the network.

LAN Design For High Availability

Properly needs making a strong and network that is very redundant. This can be achieved by developing the LAN good and making the LAN network one of the topology at a time, we can really make it available, more fault tolerant, and redundant network. Once these things have been on place network services like TFTP, DNS and DHCP can be added to the network functionality.

Power Over Ethernet (PoE)

PoE provided over usual Ethernet unshielded twisted-pair which is also the UTP cable. Instead of getting power from the wall, IP phones and similar powered devices (PDs) can get power from the inline cable Ethernet which can carry power and provide them or power source equipment (PSE). Inline power is provided by switches.

Implementing to get power during power failure times. Taking into consideration the left out of the telephony network is still online during these power failure, then IP phones continue getting and making calls. You can deploy inline power-enable switches at the access layer among wiring closets to give inline-powered Ethernet ports to the IP phones the need for power from the wall.

LAN Quality of Service (QoS)

Quality is the issue from the enterprise campus from which of the asynchronous nature of data traffic is simple because of the ability of network ate buffer limit exceeded and packet loss. with new soft wares such as voice and video, which make sensitive to packet loss and delay, buffers cannot be allowed in the LAN QoS or any network that uses real time data.

Figure Data Traffic Oversubscription in the LANhttp://www.cisco.com/en/US/i/100001-200000/140001-150000/149001-150000/149933.jpg

This oversubscription, involved with individual traffic accumulates and the combined effects of many independent traffic start points, can give out in the egress interface buffers to get into the egress buffer. The reason that the campus switches have hardware-based buffers, which looked with the interface fast are very smaller than those which can be found on WAN buffer over the top and packets that have been dropped.

For soft wares such as voice, packet loss and delay can result in very less voice quality, QoS tools which are required to take care and to make less packet loss, delay, and variation in the delay.

The types of QoS tools that are required from end to end in the infrastructure to take care of traffic and to make sure of the voice quality:

•Traffic classification

Classification includes the packets with a given importance denoting a condition for class of service (CoS network. The time at which those marked packets are believed or not believed is thought to be the trust. Mainly given ahead to devices using the phone and definitely not to data devices (PCs).

•Queuing or scheduling

Interface queuing or involves assigning packets to one of several based on classification for expedited treatment the network.

•Bandwidth provisioning

Provisioning involves making calculations based on the required bandwidth for all soft wares that are involved in the network plus element.

WAN Infrastructure

WAN design is very much required for main function of the IP telephony operation on a unified infrastructure with many Cisco CME systems. If VoIP calls are given between sites, WAN are very much needed.

Proper network design needs the following basic information and design best practices for implementing a WAN that is as online as possible and the one that gives throughput. Proper WAN network design needs implementing end to end QoS on the WAN links.

WAN Design and Configuration Best Practices

Properly making a WAN needs making fault tolerant infrastructure links and thinking for the maybe that those links may become offline. By being cautious choosing WAN topologies, providing those with the required bandwidth, and getting to them with the WAN network as some other layer in the infrastructure topology, you can make a fault tolerant and network which is redundant.

Deployment Considerations

WAN implementations for voice infrastructures must go behind a hub and spoke topology, with one hub site in the center and many remote spoke sites which are connected into the hub site in the center.

WAN links must, when can, be built redundant to give bigger levels of fault tolerance. WAN links that are redundant given by different service providers or put up in different physical ingress/egress nodes inside the infrastructure can ensure backup bandwidth and can be connected in the point that a single link fails.

Voice and data must be unified at the WAN, like as they are unified at the LAN. QoS giving and queuing tools are basically available in a WAN networks to make sure that voice and data will be able to work on the same WAN links.

When implementing voice in a WAN network, it is recommended that we make use the bandwidth which is lower G.729 codec for all voice calls that will be traverse WAN links since this practice will cut down on bandwidth on these lower-speed links.

Lastly, G.114 of the International Telecommunication Union (ITU) tells to us that the one side delay in a voice infrastructure must be less than or equal to 150 milliseconds.

Guaranteed Bandwidth

Since voice is basically deemed an important infrastructure application, it is imperative that the giver and signaling voice traffic can always reaches its destination. Just because of this, it is very much needed to build a WAN topology and link the types that can actually give definite dedicated bandwidth. The given below WAN link tools can give definite dedicated bandwidth:

•Links using Leased lines

•Links using Frame Relay

•Links using Asynchronous Transfer Mode (ATM)

•Links with ATM-to-Frame Relay Service Interworking

•Links with Multiprotocol Label Switching (MPLS)

•Links with Cisco Voice and Video Enabled IP Security VPN (IP Sec V3PN)

Best Effort Bandwidth

WAN topologies that are not able to give definite dedicated bandwidth to make sure that the infrastructure traffic will get to its receiver, even if the information is important. These topologies are very much troublesome for voice traffic, not just because they give no proper mechanisms to give definite network throughput, but also since they give no shaping of the traffic, fragmentation of the packet and interleaving, Mechanisms for queuing, and also the end to end QoS to make sure that important traffic like voice will be given priority is being sent.

The WAN network topologies given below are examples of best effort networks:

•The Internet

•DSL

•Cable

•Satellite

•Wireless

WAN Quality Of Service (QoS)

Before making voice and video data traffic on an infrastructure, it is required to make sure that there can be enough bandwidth for all needed soft wares. Then this bandwidth has been given, voice priority queuing should be done on all the interfaces. This queuing is necessary since it helps to reduce jitter and also packet loss if an explosion of traffic overflows a buffer. This queuing necessity is equal to the one for the LAN network.

Next, the WAN typically needs more mechanisms like shaping the traffic to make sure that WAN links are not only sending more traffic more than which they can handle, which can cause packets being dropped.

The sections given below tells some of the most critical features and tools to be considered when building a WAN to run both voice and data traffic:

•Provisioning of Bandwidth

•Prioritization of Traffic

•Techniques to improve link efficiency

• Shaping of Traffic

Cisco CallManager Express Security Best Practices

Cisco CallManager Express (Cisco CME) provides integrated IP communications on Cisco IOS routers. Therefore, the same security best practices recommended for all Cisco IOS voice-enabled routers also apply to Cisco Unified CME. In addition, we should implement Cisco Unified CME system-specific security practices to provide additional security protection.

Here we discuss about how to set up the Cisco Unified CME using the CLI to prevent users from intentionally or accidentally gaining system-level control from the GUI and local or remote CLI access.

Securing GUI Access

A Cisco IOS router checks for authentication an administrator CLI login with only the enable password, and ip http authentication enable is the basic setting for HTTP gain access. If the system administrator or the phone user has the exact password as the router’s enable password, they can gain access into privilege mode of the Cisco IOS in HTTP. A usual IP phone user could then unintentionally change the Cisco CME information, or erase Flash, or can also reload the router when getting in to the URL:

http://cme-ip-address/

We must make sure the following commands are used in Cisco Unified CME to use AAA or local authentication are configured to avoid a usual user from getting access to the enable password and there by having access to the system administrator page:

ip http authentication aaa

or

ip http authentication local

Configuring Basic Cisco Unified CME Access Security

The followings gives an basic idea of the security that can be used in the access layer in the Cisco CME.

•Setting Local and Remote System Access

•Restricting Access to tty

•Configuring SSH Access

•Using ACLs for SNMP Access

•Disabling Cisco Discovery Protocol

•Configuring COR for Incoming and Outgoing Calls

•Restricting Outgoing Calling Patterns

Cisco CallManager Express Security for Telephony

There are a lot of security measures that can be taken to protect the telephony services in an office. Some of the security best practices concerned with IP telephony that can be implemented are:

•IP Phone Registration Control

•Monitoring IP Phone Registration

•Call Activity Monitoring and Call History Logging

•COR for Incoming/Outgoing Calls to Prevent Toll Fraud

•After-hours Blocking to Restrict Outgoing Calling Pattern-Toll Fraud

Cisco CallManager Express with NAT and Firewall

There are security services that can be implemented in the Network Address Translator and the Firewall which help keep the whole network secure thus providing security to IP telephony as well.

Managing and Monitoring Cisco CME Systems

There are many ways one can monitor and manage the Cisco CME systems. We will discuss some of the most used and efficient ways to configure a network to be monitored which in turn allows us to manage it more efficiently and effortlessly.

Configuring and Monitoring via Network Management Systems using Cisco CME AXL/SOAP Interface

You can integrate Cisco Unified CME with network management applications by using the Cisco Unified CME XML Layer (AXL) application programming interface (API). The AXL API gives a way to insert, retrieve, update, and remove data from the Cisco CME database by using an XML SOAP interface. The AXL API allows programmatic access to Cisco CME data in the form of XML instead of making use of a Dynamic Link Library (DLL). The AXL API methods which are requested are done using a both HTTP and SOAP. The HTTP payload is encapsulated in SOAP, which is essentially an XML remote procedure call protocol. When a user requests it sends the XML data to the to the Cisco CME server, which returns an AXL response encapsulated in a SOAP message.

The Cisco CME AXL/SOAP Interface

The Cisco Unified CME AXL/SOAP APIs provide many capabilities for monitoring and configuring IP phones and extensions.

For monitoring, Cisco Unified CME AXL/SOAP APIs support the following:

•Getting static information

–ISgetGlobal—Gets global information

–ISgetDevice—Gets device information

–ISgetExtension—Gets extension information

•Getting dynamic information

–ISgetEvtCounts—Gets the number of events recorded in the buffer

–ISgetDevEvts—Gets device events if IP phones are in the register, unregister, or decease state

–ISgetExtEvts—Gets extension events (the virtual voice port is up or down)

•Setting information (configuring) and executing CLI

–ISsetKeyPhones—Sets the "key" phone

Testing the Cisco CME AXL/SOAP Interface

You might use the test page (xml-test.html) that is available with the Cisco Unified CME GUI files to verify that the Cisco CME router and make sure that it is set up correctly to respond to AXL/SOAP requests. The following are the steps to set up and run the test page:

Step 1 Load xml-test.html into Flash.

Step 2 Configure the following on the Cisco Unified CME router:

Router(config)# ip http server

Router(config)# ip http path:flash

Router(config)# telephony-service mode

Router(config)# log password abcd

Router(config)# xmltest

Step 3 Enter the following URL in the browser:

http://ip-address of router/ISApi/AXL/V1/soapisapi.is

Step 4 When the Login window opens, log on as follows:

Username: any non-empty string

Password: abcd

Step 5 In the test page, input content into the form. The XML request is written to the form at the bottom. Scroll to the bottom of the page and click Submit.

Step 6 Try the preceding steps on your system. If you receive any errors, the following debugs on the router might help:

Router# debug ip http appinout

Router# debug ip http appdetail

Cisco CME 4.0 XML Configuration example

The following is an example Cisco Unified CME 4.0 XML configuration:

ip http server

! Enables http server

ixi transport http

no shutdown

! Assigns http as the transport method of IXI

ixi application cme

no shutdown

! Enables IXI’s CME application

telephony-service

xml user admin password cisco 15

! Configures privilege for CME XML interface

Managing Cisco CME Systems

There are again many ways that can be used to manage Cisco CME systems which are used by many network administrators. It depends on the network environment to decide on the best method that can be followed to manage the network. Here we will be discussing about the simple ways of managing a more generic network.

Managing a Standalone Cisco CME system

The network model that is used here shows a Cisco CME system branch office that connects to a SP VoIP network.

Figure Managing a Standalone Cisco Unified CME Systemhttp://www.cisco.com/en/US/i/100001-200000/140001-150000/149001-150000/149587.jpg

To manage a standalone Cisco Unified CME system, we recommend that we provision or configure the system by using the Cisco Unified CME Quick Configuration Tool (QCT) 3.0 to setup your system with basic functionality. we can, as option, use the CLI, the Cisco Unified CME setup utility, or the Cisco Unified CME GUI. This is sufficient for simple moves, adds, changes to the phones, and basic configuration changes for a standalone or single-site deployment.

Managing a Multisite Cisco CME Networks

Figure Managing a Multisite Cisco Unified CME NetworkCisco CME can also be deployed in a large-scale enterprise networks or in managed-services network. The network that is used here shows multiple small scale and medium businesses or enterprise branch office that uses Cisco CME and is connected to the SP VoIP network.http://www.cisco.com/en/US/i/100001-200000/150001-160000/158001-159000/158019.jpg

When deploying Cisco Unified CME systems in a multisite environment, provisioning, configuring, and managing only one Cisco Unified CME system at a time is insufficient.

Integrated Research Prognosis

Integrated Research Prognosis is a Cisco Partner tool that can be used for monitoring Cisco Unified CME and Cisco Unity Express. Prognosis provides the following monitoring functions:

•Call quality monitoring—Monitors latency, packet loss, jitter and MOS scoring

•Availability monitoring —Monitors dash board view of phone, device and call availability; monitors percentage of phones and devices up and down

•Call detail metrics—Monitors call types and route patterns, origin and duration of calls

•Key phone metrics—Monitors offhook, registration, mac-address data

•Configuration metrics—Monitors phone, h323 gateway, dial-peer, telephony-service, software/hardware inventory

•Systems and protocol monitoring—Monitors CPU and process memory, software version, application/voice traffic

Summary

Cisco CallManager Express gives telephony features needed by business users to make sure they meet the conditions of the small office. The Cisco unified Services Router gives big reliability and many more applications which includes, IP telephony, Virtual Private Network, firewalls, encryption techniques, dial access, Power over Ethernet with Ethernet Switching, and content networking, all within a single platform, which is easy to implement and manage, which results in a very low total cost of ownership (TCO).

As the business becomes big Cisco CME could be very easily upgraded to a Cisco CME big scale IP telephony solution. All the hardware and the software used in Cisco CME is fully workable with Cisco CME and Cisco Unified Survivable Remote Site Telephony (SRST), giving the customers protection for their investment.

References

Reference 1

www.cisco.com

Reference 2

http://www.cisco.com/en/US/prod/collateral/voicesw/ps6788/vcallcon/ps4625/product_data_sheet0900aecd8041c303.html

Reference 3

https://learningnetwork.cisco.com/servlet/JiveServlet/previewBody/6346-102-1-20737/CCNA-Voice%20VoIP.pdf

Reference 4

http://www.cisco.com/en/US/docs/voice_ip_comm/unity_exp/rel2_1/ccm_gui/cmeguigd.html