10 Most Common Telecommunications interview questions
2- What is the need of CPG message in ISUP protocol?
– CPG message is sent by the switch towards originator.
– When the switch receives the setup, the call is forwarded.
– When the message is sent it is signaled that the call is progress.
– During the setup or active phase of a call, a message is sent.
– This signifies the relayed to the originating has occurred.
3- What is protocol testing? What types of tool used in telecom testing?
– Testing the functionality of the node to some standard message flow for compliance is known as protocol testing.
– Tester is used to send the standard message to the node that is under test.
– The testing tools used for protocol testing are:
1. Glomosim simulator – To test 100 nodes on single CPU.
2. Abacus5000 – To test SIP.
3. Etherpeek – To test IP.
4. Nethawk – for SS7 testing.
5. Wireshasrk – for SS7/IP testing.
6. K1297- for testing G20(tektronics).
4- What is MTU?
– Maximum Transmission Unit refers to the largest packet size.
– MTU is for passing a communication protocol for a given layer.
– Communication interfaces such as NIC, serial port are associated with MTU parameters.
– MTU might be a fixed unit as per Ethernet recommended standards.
– Higher band-width efficiency is achieved with a higher MTU.
5-What is bridging?
– One of the forward techniques to use in packet-switched networks.
– Bridging makes no assumptions about the address location of the network.
– Flooding and examination of the source addresses are the building blocks for received packet headers for locating unknown devices.
– The address of the device and its location is recorded in MAC address table for further broadcasting, after locating the device.
– Bridging refers to Transparent bridging that predominates in Ethernet.
– Source route bridging is used for token ring networks.
6-What is Impulse Response?
– Impulse Response of a system is the result that is presented with a brief input signals.
– Linear, Time-Invariant Systems are characterized by the response of their impulses.
– It is easy to analyze the systems that implements transfer functions. This is done by Laplace transform of the impulse response function.
– The output of the system can be determined in time domain by convolution of the input function with the impulse response function.
– The response of impulse and the response of Kronecker delta input are finite, as it settles zero in a finite number of interval samples.
– This process is done by Finite Impulse Response filter.
7-What is broadband?
– Broadband is an internet access with high speed.
– Unlike dial-up connection, broadband connection is permanently connected.
– It allows internet and telephone calls to take place simultaneously. No new land line is required.
– Modulation is done in broadband on signals to transform data better.
8-Explain about Infinite Impulse Response?
– IIR is one of the properties of signal processing systems.
– An impulse response function that is none-zero over an infinite length of time is available in IIR systems.
– An analog filter by name RC filter is made up of a single resistor for feeding into a node.
– This is shared with a single capacitor.
– An exponential impulse response is available in this filter that is characterized by an RC time constant.
9-Explain about Common-Mode Rejection Ration?
– CMRR is used for measuring the tendency of the device that is to reject the input signals.
– These signals can be from both input leads.
– CMRR at a high level is important, as the signals of interest are represented by a small set of fluctuations of voltage.
– The voltage fluctuations are superimposed on, possibly a large voltage offset.
– Superimposition of the signals might also be done, when the information of relevance is contained in the voltage difference between the two signals.
10- Explain about Common-Mode Rejection Ration?
– CMRR is used for measuring the tendency of the device that is to reject the input signals.
– These signals can be from both input leads.
– CMRR at a high level is important, as the signals of interest are represented by a small set of fluctuations of voltage.
– The voltage fluctuations are superimposed on, possibly a large voltage offset.
– Superimposition of the signals might also be done, when the information of relevance is contained in the voltage difference between the two signals.