Cisco Systems OL-8978-02 manual How a Call Is Made, 55-8

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Chapter 55 Configuring a VoIP Network

Understanding How VLANs Work

•One or two T1 digital ports for connecting to the following:

–PSTN using FXO emulation

–T1 channel bank using FXS emulation

–PBX through a trunk (tie) line using ear and mouth (E&M) emulation

These ports can be used to integrate a VoIP network with POTS devices, PBXs, or the PSTN.

To configure the Cisco VG200, refer to the documentation that shipped with the gateway.

How a Call Is Made

An IP phone connects to a LAN either through a hub port or a switch port. The IP phone boots up and uses DHCP to get its IP address and the IP address of its TFTP file server. The IP phone uses its IP address to talk to the TFTP server and gets its configuration file. The configuration file includes the IP address of the phone’s Cisco CallManager(s). The phone then talks with Cisco CallManager and registers itself. Each time a phone boots up, it might get a different IP address. Cisco CallManager knows how to associate a consistent user phone number to a particular phone by using the MAC address of the phone. Cisco CallManager always maintains a table mapping the phone MAC address and phone number. Each time a phone registers, the table is updated with the new IP address. During the registration, Cisco CallManager downloads the key pad template and the feature capability for the phone. It tells the phone which run-time image it should use. The phone then goes to the TFTP server to get its run-time image. Each phone has a dedicated TCP connection to Cisco CallManager called the control channel. All control information, such as key pressing, goes from the phone to Cisco CallManager through this channel. Instructions to generate ring tone, busy tone, and so on comes from Cisco CallManager to the phone through this channel.

Cisco CallManager stores the IP-address-to-phone-number mapping (and vice versa) in its tables. When a user wants to call another user, the user keys in the called party’s phone number. Cisco CallManager translates the phone number to an IP address and generates an IP packet version of the ring tone to the called IP phone through the TCP connection. When the called IP phone receives the packet, it generates a ring tone. When the user picks up the phone, Cisco CallManager instructs the called IP phone to start talking with the calling party and removes itself from the loop. From this point on, the call goes between the two IP phones through the Real-Time Transport Protocol (RTP) which runs over the User Datagram Protocol (UDP). Because the voice packets are sensitive to delays, TCP is not suitable for voice transmission because the timeouts and retries increase the delay between the packets. When any change occurs during the call due to a feature being pressed on one of the phones, or one of the users hanging up or pressing the flash button, the information goes to Cisco CallManager through the control channel.

If a call is made to a number outside of the IP PBX network, Cisco CallManager routes the call to an analog or digital trunk gateway which routes it to the PSTN.

Understanding How VLANs Work

This section describes the native VLANs and the auxiliary VLANs. This section uses the following terminology:

•Auxiliary VLAN—Separate VLAN for IP phones

•Native VLAN—Traditional VLAN for data

•Auxiliary VLAN ID—VLAN ID of an auxiliary VLAN

•Native VLAN ID—VLAN ID of a native VLAN

Catalyst 6500 Series Switch Software Configuration Guide—Release 8.7

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Contents A P T E R 55-1Cisco IP Phone 55-255-3 55-4 Access Gateways Cisco CallManagerAnalog Station Gateway 55-5FXS Interface Features Analog Trunk GatewayDigital Trunk Gateway 55-6Digital Signal Processing Per T1/E1 Port Converged Voice GatewayLink Management 55-7How a Call Is Made 55-8Switch-to-Phone Connections 55-9Voice-Related CLI Commands CLI Commands Ethernet Module1 WS-X6608-T1/E12 WS-X6624-FXS3Set port inlinepower Set inlinepower defaultallocation Show port inlinepower55-11 Configuring Per-Port Power ManagementShow environment power 55-12 Task CommandShow module mod 55-13 Power Management ModesShow version mod 55-14 Power RequirementsPhone Class Required Power W Available Power Wall-Powered PhonesPowering Off the Phone Phone Removal55-16 Phone Detection SummaryHigh-Availability Support Setting the Power Mode of a Port or a Group of Ports Setting the Default Power AllocationSet port inlinepower mod/port auto static 55-1755-18 Set inlinepower notify-threshold percentageShow port inlinepower mod /port detail Displaying the Switch Power Environment for Modules Show environment power modConsole show port inlinepower 4/1 detail Console enable show environment powerConfiguring the Auxiliary VLANs on Catalyst LAN Switches Enter the set port auxiliaryvlan mod/port auxvlanid commandUnderstanding the Auxiliary VLANs 55-20Auxiliary Vlan Configuration Guidelines Configuring the Auxiliary VLANsSet port auxiliaryvlan mod /ports vlan Untagged dot1p noneVerifying the Auxiliary Vlan Configuration Disabling the Auxiliary VLANs Until an IP Phone is DetectedKeyword Action 55-2255-23 Configuring the Access GatewaysConfiguring a Port Voice Interface Displaying a Port Voice Interface Configuration Displaying the FDL StatisticsShow port voice interface mod /port Show port voice fdl mod /portDisplaying the Port Configuration for the Individual Ports Console enable show port voice fdl 7/1-3Field Description Show port mod /portConsole show port Port T1/E1 Pstn Interface Module55-26 55-27 Port FXS Analog Interface Module 55-28Displaying the Active Call Information Show port voice active mod/portAll call conference transcode ipaddr 55-29Console show port voice active 3/2 55-30Console show port voice active 55-31 Configuring QoS in the Cisco IP PhoneUnderstanding How QoS Works in the Cisco IP Phone Configuring QoS in the Cisco IP Phone Setting the Phone Access Port Trust ModeSet port qos mod/ports...trust-ext trusted UntrustedConfiguring a Trusted Boundary to Ensure Port Security Setting the Phone Access Port CoS ValueVerifying the Phone Access Port QoS Configuration 55-33QoS and Cisco IP Phone Configuration QoS, Cisco IP Phone, and PC ConfigurationSupported Cisco IP Phones 55-34Trusted Boundary Configuration Guidelines 55-35Configuring a Trusted Boundary 55-36Default Configuration Specifying a Cisco IP Phone as the Trust DeviceVerifying a Port’s Trust-Device State 55-37Understanding SmartPorts Macros 55-3855-39 SmartPorts-Cisco IP PhoneSmartPorts-Cisco Softphone SmartPorts Guidelines and Restrictions Command Description Ciscoipphone Command OutputCLI Interface for SmartPorts 55-41Ciscosoftphone Command Output Console enable set port macro 3/1 ciscoipphone vlanConsole enable set port macro 3/1 ciscosoftphone vlan Detailed SmartPorts StatementsHow to Use SmartPorts in Your Network Ciscoipphone Macro StatementCiscosoftphone Macro Statement Keyword Port Type55-44 SmartPorts Enhancements in Software ReleaseCiscorouter SmartPorts Template Ciscoswitch SmartPorts Template Ciscodesktop SmartPorts Template55-45 Set port macro mod/port ciscodesktop vlan vlanCiscoipphone SmartPorts Template Ciscosoftphone SmartPorts Template55-46 Set port macro mod/port ciscosoftphone vlan nativevlanConfiguring User-Definable SmartPorts Macros Global SmartPorts TemplateOverview 55-47Using the CLI to Configure User-Definable SmartPorts Macros Console enable set macro name videophoneCreating User-Defined Macros 55-4855-49 Modifying Existing User-Defined MacrosDefining Variables 55-50 Using Special VariablesApplying a User-Defined Macro 55-51 Console enable set port macro 3/2 videophoneConsole enable set port macro 3/7 videophone Displaying Macros Displaying Macro VariablesShow macro name nameofmacro show macro all 55-5255-53 Clearing Macros and Macro VariablesClear macro name nameofmacro clear macro all 55-54 Displaying Macro Port MappingsShow macro map all name nameofmacro port mod/port 55-55 Configuring a Macro within a MacroConsole enable show macro map port 3/2 55-56

OL-8978-02 specifications

Cisco Systems OL-8978-02 is a comprehensive training curriculum designed to enhance the skills and knowledge of network professionals seeking to advance their careers in network management and security. This curriculum offers a significant focus on Cisco networking technologies and concepts, ensuring that learners are well-equipped to handle the intricacies of modern network environments.

One of the primary features of OL-8978-02 is its in-depth coverage of foundational networking concepts, which are crucial for effective network administration. The curriculum includes detailed modules on networking fundamentals, such as OSI and TCP/IP models, LAN and WAN architectures, and network protocols. This solid foundation enables learners to understand how different networking components interact and function together, forming the backbone of corporate and enterprise environments.

In addition to foundational knowledge, OL-8978-02 integrates a strong focus on security technologies and practices. Considering the increasing prevalence of cyber threats, the course emphasizes the importance of implementing robust security measures. Participants will learn about firewalls, intrusion prevention systems, VPNs, and other critical security technologies. This focus ensures that learners are prepared to safeguard networks against evolving security threats, a necessity in today’s digital landscape.

Another distinguishing characteristic of the OL-8978-02 curriculum is its emphasis on hands-on experience. The program often includes practical labs and simulations, allowing participants to apply theoretical knowledge in real-world scenarios. This experiential learning approach is pivotal for solidifying skills and boosting confidence in network management tasks.

Furthermore, OL-8978-02 addresses the latest advancements in networking technology, including software-defined networking (SDN) and cloud computing. By introducing emerging technologies, this curriculum ensures that professionals remain ahead of the curve, ready to adapt to the future demands of networking.

Finally, Cisco Systems OL-8978-02 positions itself not only as an educational tool but also as a career catalyst, providing learners with skills that are highly sought after in the IT job market. Upon completion, participants often find themselves well-prepared for various Cisco certifications, which can enhance their employability and professional growth opportunities in a competitive landscape. Through its thorough approach, OL-8978-02 plays a vital role in shaping the next generation of network professionals.
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