1. What is option 150 and option 66 in DHCP?
DHCP option 150 provides the IP addresses of a list of TFTP servers. DHCP option 66 gives the IP address or the hostname of a single TFTP server.
Cisco IP Phones download their configuration from a TFTP server. When a Cisco IP Phone starts, if it does not have both the IP address and TFTP server IP address pre-configured, it sends a request with option 150 to the DHCP server to obtain this information.
DHCP option 66 only supports the IP address or the hostname of a single TFTP server. We can specify the next server (TFTP server) both globally or specific to a pool. If the next server is configured in both places, then the IP specified under the pool will be used.
2. Explain Cisco UC Architecture?
Cisco Unified Communications (UC) is an IP-based communications system integrating voice, video, data, and mobility products and applications. It enables more effective, secure communications and can transform the way in which we communicate.
3. What is the CUCM Cluster?
A cluster is a set of networked servers that can be configured to provide specific services per server. Some cluster servers can be configured to provide CUCM services while other servers can provide Computer Telephony Integration (CTI), Trivial File Transfer Protocol (TFTP), and other media services such as conferencing or music on hold (MOH) These services can be provided by the subscribers and the publisher and can be shared by all servers.
A cluster consists of one publisher and a total maximum of 20 servers (nodes) running various services, including TFTP, media resources, conferencing, and call processing. You can have a maximum of eight nodes for call processing (running the Cisco Call Manager service).
4. What are ANI and DNIS?
Automatic Number Identification (ANI) is a telephony service that allows the receiver of a phone call to capture and display the phone number of the phone that originated the call and is mainly in place for billing purposes.
A dialed number Identification service (DNIS) is a service offered by telecom providers to their commercial customers, letting them know what number was dialed for each incoming call. The data is sent as a series of touch-tone digits along with the call and interpreted at the destination by the PBX.
5. What are FXO and FXS?
FXS (Foreign Exchange Subscriber) is the port that actually delivers the analog line to the subscriber. In other words, it is the “plug in the wall” that delivers a dial tone, battery current and ring voltage. ... FXO (Foreign Exchange Office) is the port that receives the analog line.
6. What are T1 and E1? How many D and B channels do they have in the case of ISDN?
T1 and E1 are private or leased line services. T1 is used in North America, while E1 is the European equivalent. Because these lines are dedicated, point-to-point services for a single user, they have attractive attributes that are different from generic internet links.
T1 and E1 are typically used for: Accessing public Frame Relay networks or Public Switched Telephone Networks (PSTNs) for voice or fax. Merging voice and data traffic. A single T1 or E1 line can support voice and data simultaneously.
Channelized T1 ISDN PRI offers 23 B channels and 1 D channel. Channelized E1 ISDN PRI offers 30 B channels and 1 D channel. Channel 24 is the D channel for T1, and channel 16 is the D channel for E1
7. What is Dial-peer?
Dial peers are used to forwarding calls to the destination telephony device. A dial peer, also known as an addressable call endpoint, is a device that can originate or receive a call in a telephone network.
8. What are the matching criteria for incoming dial-peers and outgoing dial-peers in their order of preference?
For inbound dial peers, the destination pattern is matched against the calling number (ANI string). For outbound dial peers, the destination pattern is matched against the called number (DNIS string).
9. What is Extension Mobility?
The Cisco Extension Mobility feature, sometimes referred to as hoteling, allows a user to temporarily configure another IP telephone as his own. The user must log into that IP telephone with a username and PIN.
10. What is Call Park?
Call Park is a feature of some telephone systems that allows a person to put a call on hold at one telephone set and continue the conversation from any other telephone set. The “call park” feature is activated by pressing a preprogrammed button or a special sequence of buttons.
The Call Park feature allows you to place a call on hold, so it can be retrieved from another phone in the Cisco Call Manager system (for example, a phone in another office or in a conference room). You can define either a single directory number or a range of directory numbers for use as call park extension numbers.
