Monday 11 July 2016


GeeksQuiz Computer Science Quizzes for Geeks ! Suggest Practice Placements GATE Q&A GeeksforGeeks
GATE-CS-2016 (Set 1)

 Question 1 Out of the following four sentences, select the most suitable sentence with respect to grammar and usage.


 A I will not leave the place until the minister does not meet me.
 B I will not leave the place until the minister doesn’t meet me. C I will not leave the place until the minister meet me. D I will not leave the place until the minister meets me GATE-CS-2016 (Set 1) Discuss it Question 2 A rewording of something written or spoken is a ______________. A paraphrase B paradox C paradigm D paraffin English GATE-CS-2016 (Set 1) Discuss it Question 3 Archimedes said, “Give me a lever long enough and a fulcrum on which to place it, and I will move the world.” The sentence above is an example of a ___________ statement. A figurative B collateral C literal D figurine English GATE-CS-2016 (Set 1) Discuss it Question 4 If ‘relftaga’ means carefree, ‘otaga’ means careful and ‘fertaga’ means careless, which of the following could mean ‘aftercare’? A zentaga B tagafer C tagazen D relffer General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 5 A cube is built using 64 cubic blocks of side one unit. After it is built, one cubic block is removed from every corner of the cube. The resulting surface area of the body (in square units) after the removal is __________. A 56 B 64 C 72 D 96 General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 6 A shaving set company sells 4 different types of razors, Elegance, Smooth, Soft and Executive. Elegance sells at Rs. 48, Smooth at Rs. 63, Soft at Rs. 78 and Executive at Rs. 173 per piece. The table below shows the numbers of each razor sold in each quarter of a year. GATECS161 Which product contributes the greatest fraction to the revenue of the company in that year? A Elegance B Executive C Smooth D Soft General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 7 Indian currency notes show the denomination indicated in at least seventeen languages. If this is not an indication of the nation’s diversity, nothing else is. Which of the following can be logically inferred from the above sentences? A India is a country of exactly seventeen languages. B Linguistic pluralism is the only indicator of a nation’s diversity. C Indian currency notes have sufficient space for all the Indian languages. D Linguistic pluralism is strong evidence of India’s diversity. General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 8 Consider the following statements relating to the level of poker play of four players P, Q, R, and S. I P always beats Q II. R always beats S III. S loses to P only sometimes IV. R always loses to Q Which of the following can be logically inferred from the above statements? (i) P is likely to beat all the three other players (ii) S is the absolute worst player in the set A (i) only B (ii) only C (i) and (ii) D neither (i) nor (ii) General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 9 If f(x) = 2x7 + 3x - 5 Which of the following is a factor of f(x)? A (x3 + 8) B (x - 1) C (2x - 5) D (x + 1) General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 10 In a process, the number of cycles to failure decreases exponentially with an increase in load. At a load of 80 units, it takes 100 cycles for failure. When the load is halved, it takes 10000 cycles for failure. The load for which the failure will happen in 5000 cycles is ________. A 40.00 B 46.02 C 60.01 D 92.02 General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 11 Let p, q, r, s represent the following propositions. p: {8, 9, 10, 11, 12} q: x is a composite number r: x is a perfect square s: x is a prime number gatecs20162 Note : This question was asked as Numerical Answer Type. A 8 B 9 C 11 D 12 GATE-CS-2016 (Set 1) Discuss it Question 12 Let an be the number of n-bit strings that do NOT contain two consecutive 1s. Which one of the following is the recurrence relation for an gatecs20163 A A B B C C D D GATE-CS-2016 (Set 1) Discuss it Question 13 gatecs20164 Note : This question was asked as Numerical Answer Type. A 0 B 1 C 2 D 3 Numerical Methods and Calculus GATE-CS-2016 (Set 1) Discuss it Question 14 A probability density function on the interval [a, 1] is given by 1 / x2 and outside this interval the value of the function is zero. The value of a is : Note : This question was asked as Numerical Answer Type. A -1 B 0 C 1 D 0.5 Probability GATE-CS-2016 (Set 1) Discuss it Question 15 Two eigenvalues of a 3 x 3 real matrix P are (2 + √ -1) and 3. The determinant of P is _____ Note : This question was asked as Numerical Answer Type. A 0 B 1 C 15 D -1 Linear Algebra GATE-CS-2016 (Set 1) Discuss it Question 16 Consider the Boolean operator # with the following properties: x#0 = x, x#1 = x', x#x = 0 and x#x' = 1 Then x#y is equivalent to A x'y + x'y B xy' + (xy) C x'y + xy D xy + (xy)' GATE-CS-2016 (Set 1) Discuss it Question 17 The 16-bit 2’s complement representation of an integer is 1111 1111 1111 0101; its decimal representation is Note : This question was asked as Numerical Answer Type. A 10 B 11 C -10 D -11 Number Representation GATE-CS-2016 (Set 1) Discuss it Question 18 We want to design a synchronous counter that counts the sequence 0-1-0-2-0-3 and then repeats. The minimum number of J-K flip-flops required to implement this counter is Note : This question was asked as Numerical Answer Type. A 1 B 2 C 4 D 5 Digital Logic & Number representation GATE-CS-2016 (Set 1) Discuss it Question 19 A processor can support a maximum memory of 4 GB, where the memory is word-addressable (a word consists of two bytes). The size of the address bus of the processor is at ____ least bits. Note : This question was asked as Numerical Answer Type. A 16 B 31 C 32 D None Computer Organization and Architecture GATE-CS-2016 (Set 1) Discuss it Question 20 A queue is implemented using an array such that ENQUEUE and DEQUEUE operations are performed efficiently. Which one of the following statements is CORRECT (n refers to the number of items in the queue)? A Both operations can be performed in O(1) time B At most one operation can be performed in O(1) time but the worst case time for the other operation will be Ω(n) C The worst case time complexity for both operations will be Ω(n) D Worst case time complexity for both operations will be Ω(log n) Queue GATE-CS-2016 (Set 1) Discuss it Question 21 Consider the following directed graph. GATECS20167 The number of different topological orderings of the vertices of the graph is Note : This question was asked as Numerical Answer Type. A 1 B 2 C 4 D 6 Graph Traversals GATE-CS-2016 (Set 1) Discuss it Question 22 Consider the following C program. void f(int, short); void main() { int i = 100; short s = 12; short *p = &s; __________ ; // call to f() } Run on IDE Which one of the following expressions, when placed in the blank above, will NOT result in a type checking error? A f(s, *s) B i = f(i,s) C f(i,*s) D f(i,*p) Functions GATE-CS-2016 (Set 1) Discuss it Question 23 The worst case running times of Insertion sort, Merge sort and Quick sort, respectively, are: A Θ(n log n), Θ(n log n) and Θ(n2) B Θ(n2), Θ(n2) and Θ(n Log n) C Θ(n2), Θ(n log n) and Θ(n log n) D Θ(n2), Θ(n log n) and Θ(n2) Analysis of Algorithms Sorting GATE-CS-2016 (Set 1) Discuss it Question 24 Let G be a weighted connected undirected graph with distinct positive edge weights. If every edge weight is increased by the same value, then which of the following statements is/are TRUE? P: Minimum spanning tree of G does not change Q: Shortest path between any pair of vertices does not change A P only B Q only C Neither P nor Q D Both P and Q Graph Minimum Spanning Tree GATE-CS-2016 (Set 1) Discuss it Question 25 Consider the following C program. #include void mystery(int *ptra, int *ptrb) { int *temp; temp = ptrb; ptrb = ptra; ptra = temp; } int main() { int a=2016, b=0, c=4, d=42; mystery(&a, &b); if (a < c) mystery(&c, &a); mystery(&a, &d); printf("%d\n", a); } Run on IDE The output of the program _____________ Note : This question was asked as Numerical Answer Type. A 2016 B 0 C 4 D 8 Pointer Basics GATE-CS-2016 (Set 1) Discuss it Question 26 Which of the following languages is generated by the given grammar? S -> aS|bS|ε GATECS20168 A A B B C C D D Regular languages and finite automata GATE-CS-2016 (Set 1) Discuss it Question 27 Which of the following decision problems are undecidable GATECS20169 A I and IV only B II and III only C III and IV only D II and IV only Undecidability GATE-CS-2016 (Set 1) Discuss it Question 28 Which one of the following regular expressions represents the language: the set of all binary strings having two consecutive 0s and two consecutive 1s? gatecs201611 A A B B C C D D Regular languages and finite automata GATE-CS-2016 (Set 1) Discuss it Question 29 Consider the following code segment. x = u - t; y = x * v; x = y + w; y = t - z; y = x * y; The minimum number of total variables required to convert the above code segment to static single assignment form is Note : This question was asked as Numerical Answer Type. A 6 B 8 C 9 D 10 Code Generation and Optimization GATE-CS-2016 (Set 1) Discuss it Question 30 Consider an arbitrary set of CPU-bound processes with unequal CPU burst lengths submitted at the same time to a computer system. Which one of the following process scheduling algorithms would minimize the average waiting time in the ready queue? A Shortest remaining time first B Round-robin with time quantum less than the shortest CPU burst C Uniform random D Highest priority first with priority proportional to CPU burst length CPU Scheduling GATE-CS-2016 (Set 1) Discuss it Question 31 Which of the following is NOT a superkey in a relational schema with attributes V, W, X, Y, Z and primary key V Y ? A V X Y Z B V W X Z C V W X Y D V W X Y Z Database Design(Normal Forms) GATE-CS-2016 (Set 1) Discuss it Question 32 Which one of the following is NOT a part of the ACID properties of database transactions? A Atomicity B Consistency C Isolation D Deadlock-freedom Transactions and concurrency control GATE-CS-2016 (Set 1) Discuss it Question 33 A database of research articles in a journal uses the following schema. (VOLUME, NUMBER, STARTPGE, ENDPAGE, TITLE, YEAR, PRICE) The primary key is (VOLUME, NUMBER, STARTPAGE, ENDPAGE) and the following functional dependencies exist in the schema. (VOLUME, NUMBER, STARTPAGE, ENDPAGE) -> TITLE (VOLUME, NUMBER) -> YEAR (VOLUME, NUMBER, STARTPAGE, ENDPAGE) -> PRICE The database is redesigned to use the following schemas. (VOLUME, NUMBER, STARTPAGE, ENDPAGE, TITLE, PRICE) (VOLUME, NUMBER, YEAR) Which is the weakest normal form that the new database satisfies, but the old one does not? A 1NF B 2NF C 3NF D BCNF ER and Relational Models GATE-CS-2016 (Set 1) Discuss it Question 34 Which one of the following protocols is NOT used to resolve one form of address to another one? A DNS B ARP C DHCP D RARP Misc Topics in Computer Networks GATE-CS-2016 (Set 1) Discuss it Question 35 Which of the following is/are example(s) of stateful application layer protocols? (i) HTTP (ii) FTP (iii) TCP (iv) POP3 A (i) and (ii) only B (ii) and (iii) only C (ii) and (iv) only D (iv) only Application Layer GATE-CS-2016 (Set 1) Discuss it Question 36 The coefficient of x12 in (x3 + x4 + x5 + x6 + ...)3 is. [This Question was originally a Fill-in-the-Blanks question] A 1 B 2 C 4 D 10 General Aptitude GATE-CS-2016 (Set 1) Discuss it Question 37 Consider the recurrence relation a1 = 8, an = 6n2 + 2n + an-1. Let a99 = k x 104. The value of K is _____ Note : This question was asked as Numerical Answer Type. A 190 B 296 C 198 D 200 Analysis of Algorithms (Recurrences) GATE-CS-2016 (Set 1) Discuss it Question 38 GATECS201612 [This Question was originally a Fill-in-the-Blanks question] A 1 B 2 C 3 D 4 Set Theory & Algebra GATE-CS-2016 (Set 1) Discuss it Question 39 Consider the following experiment. Step 1. Flip a fair coin twice. Step 2. If the outcomes are (TAILS, HEADS) then output Y and stop. Step 3. If the outcomes are either (HEADS, HEAD) or (HEADS, TAILS), then output N and stop. Step 4. If the outcomes are (TAILS, TAILS), then go to Step 1. The probability that the output of the experiment is Y is (up to two decimal places). [This Question was originally a Fill-in-the-Blanks question] A 0.33 B 0.25 C 0.5 D 0.27 Probability GATE-CS-2016 (Set 1) Discuss it Question 40 Consider the two cascaded 2-to-1 multiplexers as shown in the figure. GT20161 The minimal sum of products form of the output X is gt162 A A B B C C D D Digital Logic & Number representation GATE-CS-2016 (Set 1) Discuss it Question 41 The size of the data count register of a DMA controller is 16 bits. The processor needs to transfer a file of 29,154 kilobytes from disk to main memory. The memory is byte addressable. The minimum number of times the DMA controller needs to get the control of the system bus from the processor to transfer the file from the disk to main memory is _________ Note : This question was asked as Numerical Answer Type. A 3644 B 3645 C 456 D 1823 Computer Organization and Architecture GATE-CS-2016 (Set 1) Discuss it Question 42 The stage delays in a 4-stage pipeline are 800, 500, 400 and 300 picoseconds. The first stage (with delay 800 picoseconds) is replaced with a functionally equivalent design involving two stages with respective delays 600 and 350 picoseconds. The throughput increase of the pipeline is _______ percent. [This Question was originally a Fill-in-the-Blanks question] A 33 or 34 B 30 or 31 C 38 or 39 D 100 Computer Organization and Architecture GATE-CS-2016 (Set 1) Discuss it Question 43 Consider a carry lookahead adder for adding two n-bit integers, built using gates of fan-in at most two. The time to perform addition using this adder is A Θ(1) B Θ(Log (n)) C Θ(√ n) D Θ(n) Digital Logic & Number representation GATE-CS-2016 (Set 1) Discuss it Question 44 The following function computes the maximum value contained in an integer array p[] of size n (n >= 1) int max(int *p, int n) { int a=0, b=n-1; while (__________) { if (p[a] <= p[b]) { a = a+1; } else { b = b-1; } } return p[a]; } Run on IDE The missing loop condition is A a != n B b != 0 C b > (a + 1) D b != a Arrays GATE-CS-2016 (Set 1) Discuss it Question 45 What will be the output of the following C program? void count(int n) { static int d = 1; printf("%d ", n); printf("%d ", d); d++; if(n > 1) count(n-1); printf("%d ", d); } int main() { count(3); } Run on IDE A 3 1 2 2 1 3 4 4 4 B 3 1 2 1 1 1 2 2 2 C 3 1 2 2 1 3 4 D 3 1 2 1 1 1 2 Recursion GATE-CS-2016 (Set 1) Discuss it Question 46 What will be the output of the following pseudo-code when parameters are passed by reference and dynamic scoping is assumed? a=3; void n(x) {x = x * a; print(x);} void m(y) {a = 1; a = y - a; n(a); print(a);} void main() {m(a);} A 6, 2 B 6, 6 C 4, 2 D 4, 4 Principles of Programming Languages GATE-CS-2016 (Set 1) Discuss it Question 47 An operator delete(i) for a binary heap data structure is to be designed to delete the item in the i-th node. Assume that the heap is implemented in an array and i refers to the i-th index of the array. If the heap tree has depth d (number of edges on the path from the root to the farthest leaf), then what is the time complexity to re-fix the heap efficiently after the removal of the element? A O(1) B O(d) but not O(1) C O(2d) but not O(d) D O(d2d) but not O(2d) Heap GATE-CS-2016 (Set 1) Discuss it Question 48 Consider the weighted undirected graph with 4 vertices, where the weight of edge {i, j} g is given by the entry Wij in the matrix W gt164 The largest possible integer value of x, for which at least one shortest path between some pair of vertices will contain the edge with weight x is ________ Note : This question was asked as Numerical Answer Type. A 8 B 12 C 10 D 11 Graph Shortest Paths GATE-CS-2016 (Set 1) Discuss it Question 49 Let G be a complete undirected graph on 4 vertices, having 6 edges with weights being 1, 2, 3, 4, 5, and 6. The maximum possible weight that a minimum weight spanning tree of G can have is. [This Question was originally a Fill-in-the-Blanks question] A 6 B 7 C 8 D 9 Graph Minimum Spanning Tree GATE-CS-2016 (Set 1) Discuss it Question 50 G = (V, E) is an undirected simple graph in which each edge has a distinct weight, and e is a particular edge of G. Which of the following statements about the minimum spanning trees (MSTs) of G is/are TRUE I. If e is the lightest edge of some cycle in G, then every MST of G includes e II. If e is the heaviest edge of some cycle in G, then every MST of G excludes e A I only B II only C both I and II D neither I nor II Graph Minimum Spanning Tree GATE-CS-2016 (Set 1) Discuss it Question 51 Let Q denote a queue containing sixteen numbers and S be an empty stack. Head(Q) returns the element at the head of the queue Q without removing it from Q. Similarly Top(S) returns the element at the top of S without removing it from S. Consider the algorithm given below. gtcs7 The maximum possible number of iterations of the while loop in the algorithm is______ [This Question was originally a Fill-in-the-Blanks question] A 16 B 32 C 256 D 64 Queue GATE-CS-2016 (Set 1) Discuss it Question 52 Consider the following context-free grammars: gt8 Which one of the following pairs of languages is generated by G1 and G2, respectively gt9 A A B B C C D D Context free languages and Push-down automata GATE-CS-2016 (Set 1) Discuss it Question 53 Consider the transition diagram of a PDA given below with input alphabet ∑ = {a, b}and stack alphabet Γ = {X, Z}. Z is the initial stack symbol. Let L denote the language accepted by the PDA. gt11 A A B B C C D D GATE-CS-2016 (Set 1) Discuss it Question 54 Let X be a recursive language and Y be a recursively enumerable but not recursive language. Let W and Z be two languages such that Y reduces to W, and Z reduces to X (reduction means the standard many-one reduction). Which one of the following statements is TRUE A W can be recursively enumerable and Z is recursive. B W an be recursive and Z is recursively enumerable. C W is not recursively enumerable and Z is recursive. D W is not recursively enumerable and Z is not recursive Recursively enumerable sets and Turing machines GATE-CS-2016 (Set 1) Discuss it Question 55 The attributes of three arithmetic operators in some programming language are given below. Operator Precedence Associativity Arity + High Left Binary - Medium Right Binary * Low Left Binary The value of the expression 2 - 5 + 1 - 7 * 3 in this language is __________ ? Note : This question was asked as Numerical Answer Type. A 1 B 2 C 3 D 9 Principles of Programming Languages GATE-CS-2016 (Set 1) Discuss it Question 56 Consider the following Syntax Directed Translation Scheme (SDTS), with non-terminals {S, A} and terminals {a, b}}. gt46 Using the above SDTS, the output printed by a bottom-up parser, for the input aab is A 1 3 2 B 2 2 3 C 2 3 1 D Syntax Error Parsing and Syntax directed translation GATE-CS-2016 (Set 1) Discuss it Question 57 Consider a computer system with 40-bit virtual addressing and page size of sixteen kilobytes. If the computer system has a one-level page table per process and each page table entry requires 48 bits, then the size of the per-process page table is _________megabytes. Note : This question was asked as Numerical Answer Type. A 384 B 48 C 192 D 96 Memory Management GATE-CS-2016 (Set 1) Discuss it Question 58 Consider a disk queue with requests for I/O to blocks on cylinders 47, 38, 121, 191, 87, 11, 92, 10. The C-LOOK scheduling algorithm is used. The head is initially at cylinder number 63, moving towards larger cylinder numbers on its servicing pass. The cylinders are numbered from 0 to 199. The total head movement (in number of cylinders) incurred while servicing these requests is: Note : This question was asked as Numerical Answer Type. A 346 B 165 C 154 D 173 Input Output Systems GATE-CS-2016 (Set 1) Discuss it Question 59 Consider a computer system with ten physical page frames. The system is provided with an access sequence a1, a2, ..., a20, a1, a2, ..., a20), where each ai number. The difference in the number of page faults between the last-in-first-out page replacement policy and the optimal page replacement policy is __________ [Note that this question was originally Fill-in-the-Blanks question] A 0 B 1 C 2 D 3 Memory Management GATE-CS-2016 (Set 1) Discuss it Question 60 Consider the following proposed solution for the critical section problem. There are n processes: P0 ...Pn−1. In the code, function pmax returns an integer not smaller than any of its arguments. For all i, t[i] is initialized to zero. deadlock Which one of the following is TRUE about the above solution? A At most one process can be in the critical section at any time B The bounded wait condition is satisfied C The progress condition is satisfied D It cannot cause a deadlock Deadlock GATE-CS-2016 (Set 1) Discuss it Question 61 Consider the following two phase locking protocol. Suppose a transaction T accesses (for read or write operations), a certain set of objects {O1,...,Ok}. This is done in the following manner: Step 1. T acquires exclusive locks to O1, . . . , Ok in increasing order of their addresses. Step 2. The required operations are performed. Step 3. All locks are released. This protocol will A guarantee serializability and deadlock-freedom B guarantee neither serializability nor deadlock-freedom C guarantee serializability but not deadlock-freedom D guarantee deadlock-freedom but not serializability Transactions and concurrency control GATE-CS-2016 (Set 1) Discuss it Question 62 Consider that B wants to send a message m that is digitally signed to A. Let the pair of private and public keys for A and B be denoted gt20 represent the operation of encrypting m with a key Kx and H(m) represent the message digest. Which one of the following indicates the CORRECT way of sending the message m along with the digital signature to A? gt18 A A B B C C D D Network Security GATE-CS-2016 (Set 1) Discuss it Question 63 An IP datagram of size 1000 bytes arrives at a router. The router has to forward this packet on a link whose MTU (maximum transmission unit) is 100 bytes. Assume that the size of the IP header is 20 bytes. The number of fragments that the IP datagram will be divided into for transmission is : Note : This question was asked as Numerical Answer Type. A 10 B 50 C 12 D 13 Network Layer GATE-CS-2016 (Set 1) Discuss it Question 64 For a host machine that uses the token bucket algorithm for congestion control, the token bucket has a capacity of 1 megabyte and the maximum output rate is 20 megabytes per second. Tokens arrive at a rate to sustain output at a rate of 10 megabytes per second. The token bucket is currently full and the machine needs to send 12 megabytes of data. The minimum time required to transmit the data is _________________ seconds. A 1.1 B 0.1 C 2.1 D 2.0 Transport Layer GATE-CS-2016 (Set 1) Discuss it Question 65 A sender uses the Stop-and-Wait ARQ protocol for reliable transmission of frames. Frames are of size 1000 bytes and the transmission rate at the sender is 80 Kbps (1Kbps = 1000 bits/second). Size of an acknowledgement is 100 bytes and the transmission rate at the receiver is 8 Kbps. The one-way propagation delay is 100 milliseconds. Assuming no frame is lost, the sender throughput is __________ bytes/second. A 2500 B 2000 C 1500 D 500 Data Link Layer GATE-CS-2016 (Set 1) Discuss it There are 65 questions to complete. GATE-CS-2016 (Set 2) See Placement Course for placement preparation, GATE Corner for GATE CS Preparation and Quiz Corner for all Quizzes on GeeksQuiz.

Basics of pointer


#include
int main () {
int var = 20; /* actual variable declaration */
int *ip; /* pointer variable declaration */
ip = &var; /* store address of var in pointer variable*/
printf("Address of var variable: %x\n", &var );
/* address stored in pointer variable */
printf("Address stored in ip variable: %x\n", ip );
/* access the value using the pointer */
printf("Value of *ip variable: %d\n", *ip );
return 0;
}

OUTPUT


Address of var variable: bffd8b3h
Address stored in ip variable: bvfd8b3c
Value of *ip variable: 20

Sunday 10 July 2016


Search Titles Text The Wireshark Wiki Login SIP FrontPageRecentChangesFindPageHelpContentsSIP Immutable PageInfoAttachments Session Initiation Protocol (SIP) The Session Initiation Protocol (SIP) is an application-layer control (signaling) protocol for sessions. These sessions include Internet telephone calls, multimedia distribution, and multimedia conferences. SIP can create, modify, and terminate sessions with one or more participants. The SIP protocol is a member of the VOIPProtocolFamily. History XXX - add a brief description of SIP history Protocol dependencies SIP is commonly uses as its transport UDP (default port 5060), TCP (default port 5060) or TLS (default TCP port 5061). SIP signalling may also be compressed and delivered by Sigcomp SIP is commonly used to establish media sessions, e.g. RTP/RTCP streams carrying audio or video data, where session details are commonly negociated using SDP offers/answers PINTs and SPIRITS - Service interworking Number resolution - TRIP and ENUM (IETF Charter for ENUM) Seamless signaling - SIGTRAN and SIP-T IMPP - Instant Messaging and Presence SIMPLE - SIP for Instant Messaging and Presence Leveraging Extensions IETF Charter for SIMPLE Example traffic SIP.jpg Wireshark The SIP dissector is fully functional. You can also view SIP message statistics (Statistics | SIP...) or view SIP call flow graphs (Statistics | VoIP Calls) Preference Settings Display raw text for SIP message. Default OFF Enforce strict SIP version check (SIP/2.0). Default ON Reassemble SIP headers spanning multiple TCP segments. Default ON Reassemble SIP bodies spanning multiple TCP segments. Default ON Example capture file SampleCaptures/aaa.pcap Sample SIP and RTP traffic. Display Filter A complete list of SIP display filter fields can be found in the display filter reference Show only the SIP based traffic: sip Capture Filter You cannot directly filter SIP protocols while capturing. However, if you know the UDP or TCP or port used (see above), you can filter on that one. External links IETF Charters: SIP Session Initiation Protocol (sip) SIPPING Session Initiation Proposal Investigation (sipping) SIP More info on Session Initiation Protocol(SIP) RFC: RFC3261 SIP: Session Initiation Protocol RFC3262 Reliability of Provisional Responses in the Session Initiation Protocol (SIP) RFC3263 Session Initiation Protocol (SIP): Locating SIP Servers Implementations: osip The GNU oSIP library SIPp "SIPp is a free Open Source test tool / traffic generator for the SIP protocol" (GPL) Discussion SIP (last edited 2008-08-14 18:52:55 by GeraldCombs) Immutable PageInfoAttachments Original content on this site is available under the GNU General Public License. See the License page for details. Powered by MoinMoin and Python. Please don't pee in the pool.

Search Titles Text The Wireshark Wiki Login VoIP_calls FrontPageRecentChangesFindPageHelpContentsVoIP_calls Immutable PageInfoAttachments VoIP Calls Lea esta ayuda en español en http://wiki.wireshark.org/VoIP_calls_spanish To access the VoIP calls analysis use the menu entry "Telephony->VoIP Calls...". The current VoIP supported protocols are: SIP H323 ISUP MGCP UNISTIM with the corresponding RTP streams. See VOIPProtocolFamily for an overview of the used VoIP protocols. To try out this dialog, a small capture file containing a VoIP call can be found at SampleCaptures/rtp_example.raw.gz which contains an example H323 call including H225, H245, RTP and RTCP packets. List VoIP calls voip_calls_list.jpg The VoIP calls list shows the following information per call: Start Time: Start time of the call. Stop Time: Stop time of the call. Initial Speaker: The IP source of the packet that initiated the call. From: For H323 and ISUP calls, this is the calling number. For SIP calls, it is the "From" field of the INVITE. For MGCP calls, the EndpointID or calling number. For UNISTIM the Terminal ID. To: For H323 and ISUP calls, this is the called number. For SIP calls, it is the "To" field of the INVITE. For MGCP calls, the EndpointID or dialed number. For UNISTIM the dialed number. Protocol: Any of the protocols listed above Packets: Number of packets involved in the call. State: The current call state. The possible values are CALL SETUP: call in setup state (Setup, Proceeding, Progress or Alerting) RINGING: call ringing (only supported for MGCP calls) IN CALL: call is still connected CANCELLED: call was released before connect from the originated caller COMPLETED: call was connected and then released REJECTED: call was released before connect by the destination side UNKNOWN: call in unknown state Comment: An additional comment, this is protocol dependent. For H323 calls it shows if the call uses Fast Start or/and H245 Tunneling. Filtering a call To prepare a filter for a particular call, just select the desired call and press "Prepare Filter" button. This will create a filter in the Main Wireshark windows to filter the packets related to this call. This is specially useful when you want to connect ISUP calls according to some CIC value. VoIP calls Graph analysis voip_calls_graph.jpg To Graph analysis one or multiple calls from the VoIP List, select them from the list and then press the "Graph" button. The Graph will show the following information: Up to Ten columns representing an IP address each one. All packets that belong to the same call are colorized with the same color An arrow showing the direction of each packet in the calls The label on top of the arrow shows message type. When available, it also shows the media codec. The RTP traffic is summarized in a wider arrow with the corresponded Codec. Shows the UDP/TCP source and destination port per packet. The comment column has protocol dependent information: H323: Fast Start and H245 Tunneling ON/OFF for the packet. The SETUP message shows the calling and called number The RELEASE message shows the Q.931 Release cause code SIP: Shows if the packet is a "Request" or a "Staus" message. The INVITE message also shows the "From" and "To" fields ISUP: The format is as follows: NetworkID-Originating Point Code -> NetworkID-Destination Point Code, CIC MGCP: The MGCP Endpoint ID, and if the packet is a "Request" or "Response" message. UNISTIM: Details of the message, and the sequence #. RTP: Number of RTP packets in the stream, the duration in seconds and the SSRC field. When clicking a packet in the Graph, the selected frame will be selected in the Main Wireshark window. Playing VoIP calls Note: For the moment, this feature works only for G711 A-Law and G711 u-Law RTP streams (other codecs not implemented). To play the RTP audio stream of one or multiple calls from the VoIP List, select them from the list and then press the "Player" button: voip_calls_play1.jpg Choose an initial value for the jitter buffer and then press the "Decode button". The jitter buffer emulated by Wireshark is a fixed size jitter buffer and can efficiently be used to reproduce what clients can effectively hear during the VoIP call. You can now see all RTP streams available for the calls that you selected: voip_calls_play2.jpg Note that all RTP packets that are dropped because of the jitter buffer are reported ("Drop by Jitter Buff"), as well as the packets that are out of sequence (Out of Seq). Pressing the "Play" button plays the RTP stream from within Wireshark. A progress bar indicates the position in the stream and is synchronized amongst all RTP streams that are played. Discussion The file rtp_example.raw.gz didn't worked for me, you may try to play this capture file VoIP call instead: SampleCaptures/SIP_CALL_RTP_G711 I think the list of supported protocols and features is not complete. I have some videos on how to analyze VoIP calls using Wireshark. VoIP_calls (last edited 2011-12-09 16:41:08 by ChristopherMaynard) Immutable PageInfoAttachments Original content on this site is available under the GNU General Public License. See the License page for details. Powered by MoinMoin and Python. Please don't pee in the pool.

Thursday 7 July 2016


It's interesting to study about wireshark !
.PCAP file ....

Thursday 17 March 2016

For software agents, see Bot. For other uses of the term, see Robot (disambiguation).

ASIMO (2000) at the Expo 2005, abipedal humanoid robot.

Articulated welding robots used in a factory, a type of industrial robot.

The quadrupedal military robotCheetah, an evolution of BigDog(pictured), was clocked as the world's fastest legged robot in 2012, beating the record set by an MIT bipedal robot in 1989.[1]
robot is a mechanical or virtual artificial agent, usually an electro-mechanical machine that is guided by a computer program or electronic circuitry. Robots can be autonomous or semi-autonomous and range from humanoids such as Honda's Advanced Step in Innovative Mobility(ASIMO) and TOSY's TOSY Ping Pong Playing Robot (TOPIO) to industrial robots, medical operating robots, patent assist robots, dog therapy robots, collectively programmed swarmrobots, UAV drones such as General Atomics MQ-1 Predator, and even microscopic nano robots. By mimicking a lifelike appearance or automating movements, a robot may convey a sense of intelligence or thought of its own.

Monday 2 November 2015

Does God exist? The DNA code informs, programs a cell's behavior existence of GodAll instruction, all teaching, all training comes with intent. Someone who writes an instruction manual does so with purpose. Did you know that in every cell of our bodies there exists a very detailed instruction code, much like a miniature computer program? As you may know, a computer program is made up of ones and zeros, like this: 110010101011000. The way they are arranged tell the computer program what to do. The DNA code in each of our cells is very similar. It's made up of four chemicals that scientists abbreviate as A, T, G, and C. These are arranged in the human cell like this: CGTGTGACTCGCTCCTGAT and so on. There are three billion of these letters in every human cell!! Well, just like you can program your phone to beep for specific reasons, DNA instructs the cell. DNA is a three-billion-lettered program telling the cell to act in a certain way. It is a full instruction manual.13 existence of GodWhy is this so amazing? One has to ask....how did this information program wind up in each human cell? These are not just chemicals. These are chemicals that instruct, that code in a very detailed way exactly how the person's body should develop. Natural, biological causes are completely lacking as an explanation when programmed information is involved. You cannot find instruction, precise information like this, without someone intentionally constructing it.