--- 1/draft-ietf-ippm-reporting-00.txt 2006-10-26 05:12:14.000000000 +0200 +++ 2/draft-ietf-ippm-reporting-01.txt 2006-10-26 05:12:15.000000000 +0200 @@ -1,15 +1,19 @@ Network Working Group S. Shalunov Internet-Draft Internet2 +Expires: April 26, 2007 B. Lutzmann + F. Pouzols + October 23, 2006 + Reporting IP Performance Metrics to Users - draft-ietf-ippm-reporting-00.txt + draft-ietf-ippm-reporting-01.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -20,21 +24,21 @@ and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. - This Internet-Draft will expire on October 3, 2006. + This Internet-Draft will expire on April 26, 2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract The aim of this document is to define a small set of metrics that are robust, easy to understand, orthogonal, relevant, and easy to compute. The IPPM WG has defined a large number of richly @@ -52,28 +56,30 @@ 4.1. Delay . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.2. Loss . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.3. Jitter . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4.4. Duplication . . . . . . . . . . . . . . . . . . . . . . . 8 4.5. Reordering . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Sample Source . . . . . . . . . . . . . . . . . . . . . . . . 9 5.1. One-Way Active Measurement . . . . . . . . . . . . . . . . 9 5.2. Round-Trip Active Measurement . . . . . . . . . . . . . . 10 5.3. Passive Measurement . . . . . . . . . . . . . . . . . . . 10 6. Security Considerations . . . . . . . . . . . . . . . . . . . 11 - 7. Internationalization Considerations . . . . . . . . . . . . . 12 + 7. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 12 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 - 9. Normative References . . . . . . . . . . . . . . . . . . . . . 13 - Appendix A. Acknowledgments . . . . . . . . . . . . . . . . . . . 14 - Appendix B. TODO . . . . . . . . . . . . . . . . . . . . . . . . 15 - Appendix C. Revision History . . . . . . . . . . . . . . . . . . 16 - Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 17 - Intellectual Property and Copyright Statements . . . . . . . . . . 18 + 9. Internationalization Considerations . . . . . . . . . . . . . 14 + 10. Normative References . . . . . . . . . . . . . . . . . . . . . 14 + Appendix A. Sample Source Code for Computing the Metrics . . . . 15 + Appendix B. Example Report . . . . . . . . . . . . . . . . . . . 39 + Appendix C. TODO . . . . . . . . . . . . . . . . . . . . . . . . 40 + Appendix D. Revision History . . . . . . . . . . . . . . . . . . 41 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 42 + Intellectual Property and Copyright Statements . . . . . . . . . . 43 1. Requirements Notation The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. 2. Goals and Motivation The IPPM working group has defined many richly parameterized @@ -303,58 +309,1200 @@ An aspect of reporting relevant to security is how the reported metrics are used and how they are collected. If it is important that the metrics satisfy certain conditions (e.g., that the ISP whose network is being measured be unable to make the metrics appear better than they are), the collection mechanism MUST ensure that this is, indeed, so. The exact mechanisms to do so our outside of scope of this document and belong with discussion of particular measurement data collection protocols. -7. Internationalization Considerations +7. Acknowledgments - The reported metrics, while they might occasionally be parsed by - machine, are primarily meant for human consumption. As such, they - MAY be reported in the language preferred by the user, using an - encoding suitable for the purpose, such as UTF-8. + We gratefully acknowledge discussion with, encouragement from, and + contributions of Lawrence D. Dunn, Reza Fardid, Ruediger Geib, + Matt Mathis, Al Morton, Carsten Schmoll, Henk Uijterwaal, and + Matthew J. Zekauskas. 8. IANA Considerations This document requires no action from the IANA. -9. Normative References +9. Internationalization Considerations + + The reported metrics, while they might occasionally be parsed by + machine, are primarily meant for human consumption. As such, they + MAY be reported in the language preferred by the user, using an + encoding suitable for the purpose, such as UTF-8. + +10. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. -Appendix A. Acknowledgments +Appendix A. Sample Source Code for Computing the Metrics - The author gratefully acknowledges discussion with, encouragement - from, and contributions of Lawrence D. Dunn, Reza Fardid, - Ruediger Geib, Matt Mathis, Al Morton, Carsten Schmoll, - Henk Uijterwaal, and Matthew J. Zekauskas. + This appendix only serves for illustrative purposes. -Appendix B. TODO + /* + * reporting.c -- performance metrics reporting as in Internet Draft + * draft-ietf-ippm-reporting. + * + * Written by Stanislav Shalunov, http://www.internet2.edu/~shalunov/ + * Bernhard Lutzmann, belu@users.sf.net + * Federico Montesino Pouzols, fedemp@altern.org + * + * This file is also available, under a different (BSD-style) + * license, as part of thrulay. + */ - FIXME: This section needs to be removed before publication. + /** + * @file reporting.c + * + * @short metrics computation and reporting. + **/ - o Add references + #include + #include + #include + #include + #include + #include - o Add non-normative code for illustration + #define min(a, b) ((a) < (b) ? (a) : (b)) + #define max(a, b) ((a) > (b) ? (a) : (b)) - o Add examples (code output) + /* + * Reordering. + */ + #define loop(x) ((x) >= 0 ? (x) : (x) + (int)reordering_max) -Appendix C. Revision History + /* + * Duplication. + */ + static uint64_t *bitfield = NULL; /* Bit field used to check for + duplicated packets. */ + + /* + * Reordering. + */ + static uint64_t reordering_max; /* We have m[j-1] == number of */ + static uint64_t *reordering_m; /* We have m[j-1] == number of + j-reordered packets. */ + static uint64_t *reordering_ring; /* Last sequence numbers seen */ + static int r = 0; /* Ring pointer for next write. */ + static int l = 0; /* Counter of sequence numbers. */ + + /* + * Quantiles + * + * Reference: + * + * [1] Manku, Rajagopalan, Lindsay: "Approximate Medians and other + * Quantiles in One Pass and with Limited Memory", + * http://www-db.stanford.edu/~manku/papers/98sigmod-quantiles.pdf + */ + + #define QUANTILE_EPS 0.005 + + static uint16_t quantile_max_seq; /* Maximum number of sequences */ + static int *quantile_k; /* number of elements in buffer */ + + static double **quantile_input; /* This is the buffer where the + sequence of incoming packets is + saved. If we received enough + packets, we will write this + buffer to a quantile buffer. */ + static int *quantile_input_cnt; /* number of elements in input + * buffer */ + static int *quantile_empty_buffers; /* number of empty buffers */ + + static int *quantile_b; /* number of buffers */ + + static double **quantile_buf; + + static int *quantile_alternate; /* this is used to determine + the offset in COLLAPSE (if + weight is even) */ + + static uint64_t *quantile_inf_cnt; /* this counter is for the + additional -inf, +inf + elements we added to NEW + buffer to fill it up. */ + + typedef struct quantile { + struct quantile *next; /* pointer to next quantile + * buffer */ + int weight; /* 0 if buffer is empty, > 0 if buffer is + * full */ + int level; + double *buffer; + int pos; /* current position in buffer; used in + quantile_collapse() */ + } quantile_t; + + static quantile_t **quantile_buffer_head; + + int + reordering_init(uint64_t max) + { + reordering_max = max; + reordering_m = calloc(reordering_max, sizeof(uint64_t)); + reordering_ring = calloc(reordering_max, sizeof(uint64_t)); + if (reordering_m == NULL) { + return -1; + } else { + return 0; + } + } + + int + reordering_checkin(uint64_t packet_sqn) + { + int j; + + for (j = 0; j < min(l, (int)reordering_max) && + + packet_sqn < reordering_ring[loop(r-j-1)]; j++) { + reordering_m[j]++; + } + reordering_ring[r] = packet_sqn; + l++; + r = (r + 1) % reordering_max; + return 0; + } + + double + reordering_output(uint64_t j) + { + if (j >= reordering_max) + return -1; + else + return (double)reordering_m[j] / (l - j - 1); + } + + void + reordering_exit(void) + { + free(reordering_ring); + free(reordering_m); + } + + int + duplication_init(uint64_t npackets) + { + uint64_t bitfield_len = 0; /* Number of sectors in bitfield */ + + /* Allocate memory for bit field */ + bitfield_len = ((npackets % 64)? + (npackets / 64 + 1) : npackets / 64); + bitfield = calloc(bitfield_len, sizeof(uint64_t)); + if (bitfield == NULL) { + return -1; + } else { + return 0; + } + } + + int + duplication_check(uint64_t packet_sqn) + { + uint64_t bitfield_sec; /* Which sector in bitfield */ + uint64_t bitfield_bit; /* Which bit in sector */ + + /* Calculate sector */ + bitfield_sec = packet_sqn >> 6; + + /* Calculate bit in sector */ + bitfield_bit = (uint64_t)1 << (packet_sqn & 63); + + if (bitfield[bitfield_sec] & bitfield_bit) { + /* Duplicated packet */ + return 1; + } else { + /* Unique packet */ + bitfield[bitfield_sec] |= bitfield_bit; + return 0; + } + } + + void + duplication_exit(void) + { + free(bitfield); + } + /* Calculate binomial coefficient C(n, k). */ + int64_t + binomial (int n, int k) + { + int64_t bc = 0; + int i, m; + + /* C(n, k) = C(n, n-k) */ + k = min(k, n-k); + + if (k >= 0) { + bc = 1; + m = max(k, n-k); + + for (i = 1; i <= k; i++) { + bc = (bc * (m + i)) / i; + } + } + + return bc; + } + + int + quantile_compare(const void *d1, const void *d2) + { + if (*(double *)d1 < *(double *)d2) { + return -1; + } else if (*(double *)d1 == *(double *)d2) { + return 0; + } else { + assert(*(double *)d1 > *(double *)d2); + return 1; + } + } + + void + quantile_sort (double *list, int length) + { + qsort(list, length, sizeof(double), quantile_compare); + } + + /** + * Implementation of NEW operation from section 3.1 of paper [1]. + * + * Takes as input an empty buffer. Simply populates the quantile + * buffer with the next k elements from the input sequence, labels + * the buffer as full, and assigns it a weight of 1. + * + * If there are not enough elements to fill up the buffer, we + * alternately add -inf, +inf elements until buffer is full (-inf + * == 0, +inf == DBL_MAX). + * + * NOTE: We sort the elements in the input buffer before we copy + * them to the quantile buffer. + * + * @param seq Sequence index. + * + * @return + * @retval 0 on success. + * @retval -2 need an empty buffer. + * @retval -3 bad input sequence length. + **/ + int + quantile_new(uint16_t seq, quantile_t *q, double *input, int k, + int level) + { + int i; + + /* Check that buffer is really empty. */ + if (q->weight != 0) { + return -2; + } + + /* Sanity check for length of input sequence. */ + if (k > quantile_k[seq]) { + return -3; + } + + /* If there are not enough elements in the input buffer, fill + * it up with -inf, +inf elements. */ + for (i = k; i < quantile_k[seq]; i++) { + if (i % 2) { + input[i] = DBL_MAX; + } else { + input[i] = 0; + } + + /* Increment counter that indicates how many additional + * elements we added to fill the buffer. */ + quantile_inf_cnt[seq]++; + } + + quantile_sort(input, quantile_k[seq]); + + memcpy(q->buffer, input, sizeof(double) * quantile_k[seq]); + /* Mark buffer as full and set level. */ + q->weight = 1; + q->level = level; + + /* Update number of empty quantile buffers. */ + quantile_empty_buffers[seq]--; + + return 0; + } + + /* Implementation of COLLAPSE operation from section 3.2 of paper + * [1]. + * + * This is called from quantile_algorithm() if there are no empty + * buffers. We COLLAPSE all the full buffers, where level has + * value `level'. Output is written to the first buffer in linked + * list with level set to `level'. The level of the output buffer + * is increased by 1. All other buffers we used in the COLLAPSE + * are marked empty. */ + int + quantile_collapse(uint16_t seq, int level) + { + quantile_t *qp = NULL, *qp_out = NULL; + int num_buffers = 0; /* number of buffers with level + * `level' */ + int weight = 0; /* weight of the output buffer */ + int offset; + int i, j; + double min_dbl; + long next_pos; + long merge_pos = 0; + + /* Check that there are at least two full buffers with given + * level. Also calculate weight of output buffer. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; qp = qp->next) { + if ((qp->weight != 0) && (qp->level == level)) { + num_buffers++; + weight += qp->weight; + qp->pos = 0; + } else { + /* We mark the buffers that are not used in this + * COLLAPSE. */ + qp->pos = -1; + } + } + if (num_buffers < 2) { + return -4; + } + + /* NOTE: The elements in full buffers are sorted. So we don't + * have to do that again. + */ + /* Search for first full buffer with matching level. This is + * the buffer where we save the output. */ + for (qp_out = quantile_buffer_head[seq]; qp_out != NULL; + qp_out = qp_out->next) { + if (qp_out->pos != -1) { + break; + } + } + + /* Calculate offset */ + if (weight % 2) { + /* odd */ + offset = (weight + 1) / 2; + } else { + /* even - we alternate between two choices in each + * COLLAPSE */ + if (quantile_alternate[seq] % 2) { + offset = weight / 2; + } else { + offset = (weight + 2)/ 2; + } + quantile_alternate[seq] = (quantile_alternate[seq] + 1) % 2; + } + + /* Initialize next position of element to save. Because first + * position is at 0, we have to decrement offset by 1. */ + next_pos = offset - 1; + + for (i = 0; i < quantile_k[seq]; ) { + + /* Search for current minimal element in all buffers. + * Because buffers are all sorted, we just have to check + * the element at current position. */ + min_dbl = DBL_MAX; + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + /* Skip wrong buffers. */ + if (qp->pos == -1) { + continue; + } + + /* Check that we are not at the end of buffer. */ + if (qp->pos >= quantile_k[seq]) { + continue; + } + + /* Update minimum element. */ + min_dbl = min(min_dbl, qp->buffer[qp->pos]); + } + + /* Now process this minimal element in all buffers. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + /* Skip wrong buffers. */ + if (qp->pos == -1) { + continue; + } + + /* Now process minimal element in this buffer. */ + for (; (qp->buffer[qp->pos] == min_dbl) && + (qp->pos < quantile_k[seq]); + qp->pos++) { + + /* We run this loop `qp->weight' times. + * We check there if we are in a position + * so we have to save this element in our + * output buffer. */ + for (j = 0; j < qp->weight; j++) { + + if (next_pos == merge_pos) { + quantile_buf[seq][i] = min_dbl; + i++; + + if (i == quantile_k[seq]) { + /* We have written + * all elements to + * output buffer, so + * exit global loop. */ + goto out; + } + + /* Update next position. */ + next_pos += weight; + } + + merge_pos++; + } /* for(j = 0; j < qp->weight; j++) */ + } /* for (; (qp->buffer[qp->pos] == min_dbl) && + (qp->pos < quantile_k[seq]); qp->pos++) */ + } /* for (qp = quantile_buffer_head[seq]; qp!=NULL; + qp = qp->next) */ + } /* for (i = 0; i < quantile_k[seq]; ) */ + + out: + memcpy(qp_out->buffer, quantile_buf[seq], + sizeof(double) * quantile_k[seq]); + + /* Update weight of output buffer. */ + qp_out->weight = weight; + qp_out->level = level+1; + + /* Update list of empty buffers. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; qp = qp->next) { + if ((qp->pos != -1) && (qp != qp_out)) { + qp->weight = 0; + qp->level = 0; + } + } + quantile_empty_buffers[seq] += num_buffers - 1; + return 0; + } + + /** + * Implementation of COLLAPSE policies from section 3.4 of paper + * [1]. + * + * There are three different algorithms noted in the paper. We use + * the "New Algorithm". + * + * @param seq Sequence index. + * + * @return + * @retval 0 on success. + * @retval -1 quantiles not initialized. + * @retval -2 need an empty buffer for new operation. + * @retval -3 bad input sequence length in new operation. + * @retval -4 not enough buffers for collapse operation. + **/ + int + quantile_algorithm (uint16_t seq, double *input, int k) + { + int rc; + quantile_t *qp = NULL, *qp2 = NULL; + int min_level = -1; + + /* This should always be true. */ + if (quantile_buffer_head[seq] != NULL) { + min_level = quantile_buffer_head[seq]->level; + } else { + return -1; + } + + /* Get minimum level of all currently full buffers. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; qp = qp->next) { + if (qp->weight != 0) { + /* Full buffer. */ + min_level = min(min_level, qp->level); + } + } + + if (quantile_empty_buffers[seq] == 0) { + /* There are no empty buffers. Invoke COLLAPSE on the set + * of buffers with minimum level. */ + + rc = quantile_collapse(seq, min_level); + if (rc < 0) + return rc; + } else if (quantile_empty_buffers[seq] == 1) { + /* We have exactly one empty buffer. Invoke NEW and assign + * it level `min_level'. */ + + /* Search the empty buffer. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + if (qp->weight == 0) { + /* Found empty buffer. */ + break; + } + } + + rc = quantile_new(seq, qp, input, k, min_level); + if (rc < 0) + return rc; + } else { + /* There are at least two empty buffers. Invoke NEW on each + * and assign level `0' to each. */ + + /* Search for two empty buffers. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + if (qp->weight == 0) { + /* Found first empty buffer. */ + break; + } + } + for (qp2 = qp->next; qp2 != NULL; qp2 = qp2->next) { + if (qp2->weight == 0) { + /* Found second empty buffer. */ + break; + } + } + + if (k <= quantile_k[seq]) { + /* This could happen if we call this after we + * received all packets but don't have enough to + * fill up two buffers. */ + + rc = quantile_new(seq, qp, input, k, 0); + if (rc < 0) + return rc; + } else { + /* We have enough input data for two buffers. */ + rc = quantile_new(seq, qp, input, quantile_k[seq], 0); + if (rc < 0) + return rc; + rc = quantile_new(seq, qp2, input + quantile_k[seq], + k - quantile_k[seq], 0); + if (rc < 0) + return rc; + } + } + return 0; + } + + int + quantile_init_seq(uint16_t seq) + { + quantile_t *qp = NULL; + int i; + + if ( seq >= quantile_max_seq) + return -5; + + /* Allocate memory for quantile buffers. Buffers are linked + * lists with a pointer to next buffer. We need `quantile_b' + * buffers, where each buffer has space for `quantile_k' + * elements. */ + for (i = 0; i < quantile_b[seq]; i++) { + if (i == 0) { + /* Initialize first buffer. */ + qp = malloc(sizeof(quantile_t)); + if (qp == NULL) { + return -1; + } + quantile_buffer_head[seq] = qp; + } else { + qp->next = malloc(sizeof(quantile_t)); + if (qp->next == NULL) { + return -1; + } + qp = qp->next; + } + + /* `qp' points to buffer that should be initialized. */ + qp->next = NULL; + qp->weight = 0; /* empty buffers have weight of 0 */ + qp->level = 0; + qp->buffer = malloc(sizeof(double) * quantile_k[seq]); + if (qp->buffer == NULL) { + return -1; + } + } + /* Update number of empty quantile buffers. */ + quantile_empty_buffers[seq] = quantile_b[seq]; + + return 0; + } + + int + quantile_init (uint16_t max_seq, double eps, uint64_t N) + { + int b, b_tmp = 0; + int k, k_tmp = 0; + int h, h_max = 0; + int seq, rc; + + quantile_max_seq = max_seq; + /* Allocate array for the requested number of sequences. */ + quantile_k = calloc(max_seq, sizeof(int)); + quantile_input = calloc(max_seq, sizeof(double*)); + quantile_input_cnt = calloc(max_seq, sizeof(int)); + quantile_empty_buffers = calloc(max_seq, sizeof(int)); + quantile_b = calloc(max_seq, sizeof(int)); + quantile_buf = calloc(max_seq, sizeof(double*)); + quantile_alternate = calloc(max_seq, sizeof(int)); + quantile_inf_cnt = calloc(max_seq, sizeof(uint64_t)); + quantile_buffer_head = calloc(max_seq, sizeof(quantile_t*)); + + /* "In practice, optimal values for b and k can be computed by + * trying out different values of b in the range 1 and 30." */ + for (b = 2; b <= 30; b++) { + /* For each b, compute the largest integral h that + * satisfies: + + * (h-2) * C(b+h-2, h-1) - C(b+h-3, h-3) + + * C(b+h-3, h-2) <= 2 * eps * N + */ + for (h = 0; ; h++) { + if (((h-2) * binomial(b+h-2, h-1) - + binomial(b+h-3, h-3) + + binomial(b+h-3, h-2)) > + (2 * eps * N)) { + /* This h does not satisfy the inequality from + * above. */ + break; + } + h_max = h; + } + + /* Now compute the smallest integral k that satisfies: + * k * C(b+h-2, h-1) => N. */ + k = ceil(N / (double)binomial(b+h_max-2, h_max-1)); + + /* Identify that b that minimizes b*k. */ + if ((b_tmp == 0) && (k_tmp == 0)) { + /* Initialize values */ + b_tmp = b; + k_tmp = k; + } + + if ((b * k) < (b_tmp * k_tmp)) { + /* Found b and k for which the product is smaller than + * for the ones before. Because we want to minimize + * b*k (required memory), we save them. */ + b_tmp = b; + k_tmp = k; + } + } + + /* Set global quantile values. For now, all sequences share + the same k and b values.*/ + for (seq = 0; seq < max_seq; seq++ ) { + quantile_b[seq] = b_tmp; + quantile_k[seq] = k_tmp; + } + + /* Allocate memory for input buffer. We allocate enough space + * to save up to `2 * quantile_k' elements. This space is + * needed in the COLLAPSE policy if there are more than two + * empty buffers. Because then we have to invoke NEW on two + * buffers and thus need an input buffer with `2 * quantile_k' + * elements. */ + for (seq = 0; seq < quantile_max_seq; seq++) { + quantile_input[seq] = malloc(sizeof(double) * 2 * + quantile_k[seq]); + if (quantile_input[seq] == NULL) { + return -1; + } + quantile_input_cnt[seq] = 0; + } + + /* Allocate memory for output buffer. This buffer is used in + * COLLAPSE to store temporary output buffer before it gets + * copied to one of the buffers used in COLLAPSE. */ + for (seq = 0; seq < quantile_max_seq; seq++ ) { + quantile_buf[seq] = malloc(sizeof(double) * quantile_k[seq]); + if (quantile_buf[seq] == NULL) { + return -1; + } + } + + for (seq = 0; seq < max_seq; seq++) { + rc = quantile_init_seq(seq); + if (rc < 0) + return rc; + } + + return 0; + } + + int + quantile_value_checkin(uint16_t seq, double value) + { + int rc = 0; + + if ( seq >= quantile_max_seq) + return -5; + + quantile_input[seq][quantile_input_cnt[seq]++] = value; + + /* If we have at least two empty buffers, + * we need input for two buffers, to twice + * the value of `quantile_k'. */ + if (quantile_empty_buffers[seq] >= 2) { + if (quantile_input_cnt[seq] == + (2 * quantile_k[seq])) { + rc = quantile_algorithm(seq, quantile_input[seq], + quantile_input_cnt[seq]); + /* Reset counter. */ + quantile_input_cnt[seq] = 0; + } + } else { + /* There are 0 or 1 empty buffers */ + if (quantile_input_cnt[seq] == quantile_k[seq]) { + rc = quantile_algorithm(seq, quantile_input[seq], + quantile_input_cnt[seq]); + /* Reset counter. */ + quantile_input_cnt[seq] = 0; + } + } + return rc; + } + + int + quantile_finish(uint16_t seq) + { + int rc = 0; + + if ( seq >= quantile_max_seq) + return -5; + + if (quantile_input_cnt[seq] > 0) { + rc = quantile_algorithm(seq, quantile_input[seq], + quantile_input_cnt[seq]); + } + return rc; + } + + void + quantile_reset(uint16_t seq) + { + quantile_input_cnt[seq] = 0; + quantile_empty_buffers[seq] = quantile_b[seq]; + memset(quantile_buf[seq],0,sizeof(double) * quantile_k[seq]); + memset(quantile_input[seq],0,sizeof(double) * quantile_k[seq]); + } + + /** + * Deinitialize one quantile sequence. + **/ + void + quantile_exit_seq(uint16_t seq) + { + quantile_t *qp = NULL, *next; + + if (seq >= quantile_max_seq) + return; + qp = quantile_buffer_head[seq]; + while (qp != NULL) { + /* Save pointer to next buffer. */ + next = qp->next; + + /* Free buffer and list entry. */ + free(qp->buffer); + free(qp); + + /* Set current buffer to next one. */ + qp = next; + } + + quantile_buffer_head[seq] = NULL; + quantile_input_cnt[seq] = 0; + quantile_empty_buffers[seq] = quantile_b[seq]; + } + + void + quantile_exit(void) + { + int seq; + + /* Free per sequence structures */ + for (seq = 0; seq < quantile_max_seq; seq++) { + quantile_exit_seq(seq); + + /* Free output buffer. */ + free(quantile_buf[seq]); + + /* Free input buffer. */ + free(quantile_input[seq]); + } + + free(quantile_buffer_head); + free(quantile_inf_cnt); + free(quantile_alternate); + free(quantile_buf); + free(quantile_b); + free(quantile_empty_buffers); + free(quantile_input_cnt); + free(quantile_input); + free(quantile_k); + } + + int + quantile_output (uint16_t seq, uint64_t npackets, double phi, + double *result) + { + quantile_t *qp = NULL; + int num_buffers = 0; + int weight = 0; + int j; + long next_pos = 0; + long merge_pos = 0; + double min_dbl; + double beta; + double phi2; /* this is phi' */ + + if ( seq >= quantile_max_seq) + return -5; + + /* Check that there are at least two full buffers with given + * level. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; qp = qp->next) { + if (qp->weight != 0) { + num_buffers++; + weight += qp->weight; + qp->pos = 0; + } else { + qp->pos = -1; + } + } + if (num_buffers < 2) { + /* XXX: In section 3.3 "OUTPUT operation" of paper [1] is + * says that OUTPUT takes c => 2 full input buffers. But + * what if we just have one full input buffer? + * + * For example this happens if you run a UDP test with a + * block size of 100k and a test duration of 3 seconds: $ + * ./thrulay -u 100k -t 3 localhost + */ + + if (num_buffers != 1) { + return -1; + } + } + + /* Calculate beta and phi' */ + beta = 1 + quantile_inf_cnt[seq] / (double)npackets; + assert(beta >= 1.0); + + assert(phi >= 0.0 && phi <= 1.0); + phi2 = (2 * phi + beta - 1) / (2 * beta); + + next_pos = ceil(phi2 * quantile_k[seq] * weight); + /* XXX: If the client just sends a few packets, it is possible + * that next_pos is too large. If this is the case, decrease + * it. */ + if (next_pos >= (num_buffers * quantile_k[seq])) { + next_pos --; + } + + while (1) { + + /* Search for current minimal element in all buffers. + * Because buffers are all sorted, we just have to check + * the element at current position. */ + min_dbl = DBL_MAX; + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + /* Skip wrong buffers. */ + if (qp->pos == -1) { + continue; + } + + /* Check that we are not at the end of buffer. */ + if (qp->pos >= quantile_k[seq]) { + continue; + } + + /* Update minimum element. */ + min_dbl = min(min_dbl, qp->buffer[qp->pos]); + } + + /* Now process this minimal element in all buffers. */ + for (qp = quantile_buffer_head[seq]; qp != NULL; + qp = qp->next) { + /* Skip wrong buffers. */ + if (qp->pos == -1) { + continue; + } + + /* Now process minimal element in this buffer. */ + for (; (qp->buffer[qp->pos] == min_dbl) && + (qp->pos < quantile_k[seq]); + qp->pos++) { + + /* Increment merge position `qp->weight' + * times. If we pass the position we seek, + * return current minimal element. */ + for (j = 0; j < qp->weight; j++) { + if (next_pos == merge_pos) { + *result = min_dbl; + return 0; + } + merge_pos++; + } + } + } + } + + /* NOTREACHED */ + } + + #ifdef THRULAY_REPORTING_SAMPLE_LOOP + + #include + #include + + #ifndef NAN + #define _ISOC99_SOURCE + #include + #endif + + #define ERR_FATAL 0 + #define ERR_WARNING 1 + + void __attribute__((noreturn)) + quantile_alg_error(int rc) + { + switch (rc) { + case -1: + fprintf(stderr, "Error: quantiles not initialized."); + break; + case -2: + fprintf(stderr, "Error: NEW needs an empty buffer."); + break; + case -3: + fprintf(stderr, "Error: Bad input sequence length."); + break; + case -4: + fprintf(stderr, "Error: Not enough buffers for COLLAPSE."); + break; + default: + fprintf(stderr, "Error: Unknown quantile_algorithm error."); + } + exit(1); + } + + /** + * Will read a sample data file (first and only parameter) whose + * lines give two values per line (per received packet): measured + * packet delay and packet sequence number (in "%lf %lu" + * format). As an exception, the first line specifies the number + * of packets actually sent. Example: + * ---- + 10 + 0.101 0 + 0.109 1 + 0.12 1 + 0.10 3 + 0.14 4 + 0.15 5 + 0.13 2 + 0.09 6 + 0.1 8 + 0.091 7 + * ---- + * + * To compile this sample reporting main(): + * + * gcc -std=c99 -DTHRULAY_REPORTING_SAMPLE_LOOP reporting.c -lm + * + **/ + int + main(int argc, char *argv[]) + { + FILE *sf; + /* 'Measured data' */ + const int max_packets = 65535; + /* 'Received' packets*/ + int npackets = 0; + uint64_t packet_sqn[max_packets]; /* Fill in with sample data */ + double packet_delay[max_packets]; /* Fill in with sample data */ + uint64_t packets_sent = 0; /* Fill in with sample data */ + /* reordering */ + const uint64_t reordering_max = 100; + char buffer_reord[reordering_max * 80]; + size_t r = 0; + uint64_t j = 0; + /* Stats */ + uint64_t unique_packets = 0, packets_dup = 0; + double quantile_25, quantile_50, quantile_75; + double delay, jitter; + double packet_loss; + char report_buffer[1000]; + /* Auxiliary variables */ + int i, rc, rc2, rc3; + memset(packet_sqn,0,sizeof(uint64_t)*max_packets); + memset(packet_delay,0,sizeof(double)*max_packets); + + /* Inititalize duplication */ + rc = duplication_init(max_packets); + if (-1 == rc) { + perror("calloc"); + exit(1); + } + + /* Initialize quantiles */ + rc = quantile_init(1, QUANTILE_EPS, max_packets); + if (-1 == rc) { + perror("malloc"); + exit(1); + } + + /* Initialize reordering */ + rc = reordering_init(reordering_max); + if (-1 == rc) { + perror("calloc"); + exit(1); + } + + /* Open sample file */ + if (2 == argc) { + sf = fopen(argv[1],"r"); + } else { + fprintf(stderr, "no input file\n"); + exit(1); + } + + /* Process sample input file. */ + + /* The sender somehow tells the receiver how many packets were + actually sent. */ + fscanf(sf,"%lu",&packets_sent); + + for (i = 0; i < max_packets && !feof(sf); i++) { + + fscanf(sf,"%lf %lu",&packet_delay[i],&packet_sqn[i]); + npackets++; + + /* + * Duplication + */ + if (duplication_check(packet_sqn[i])) { + /* Duplicated packet */ + packets_dup++; + continue; + } else { + /* Unique packet */ + unique_packets++; + } + + /* + * Delay quantiles. + */ + rc = quantile_value_checkin(0, packet_delay[i]); + if (rc < 0) + quantile_alg_error(rc); + + /* + * Reordering + */ + reordering_checkin(packet_sqn[i]); + } + + /* + * Perform last algorithm operation with a possibly not full + * input buffer. + */ + rc = quantile_finish(0); + if (rc < 0) + quantile_alg_error(rc); + + rc = quantile_output(0, unique_packets, 0.25, &quantile_25); + rc2 = quantile_output(0, unique_packets, 0.50, &quantile_50); + rc3 = quantile_output(0, unique_packets, 0.75, &quantile_75); + if (-1 == rc || -1 == rc2 || -1 == rc3) { + fprintf(stderr,"An error occurred while computing delay " + "quantiles. %d %d %d\n",rc, rc2, rc3); + exit(1); + } + + /* Delay and jitter computation */ + packet_loss = packets_sent > unique_packets? + (100.0*(packets_sent - unique_packets))/packets_sent: 0; + delay = (packet_loss > 50.0)? INFINITY : quantile_50; + if (packet_loss < 25.0 ) { + jitter = quantile_75 - quantile_25; + } else if (packet_loss > 75.0) { + jitter = NAN; + } else { + jitter = INFINITY; + } + /* Format final report */ + snprintf(report_buffer, sizeof(report_buffer), + "Delay: %3.3fms\n" + "Loss: %3.3f%%\n" + "Jitter: %3.3fms\n" + "Duplication: %3.3f%%\n" + "Reordering: %3.3f%%\n", + 1000.0 * delay, + packet_loss, + 1000.0 * jitter, + 100 * (double)packets_dup/npackets, + 100.0 * reordering_output(0)); + + printf("%s", report_buffer); + + /* Deallocate resources for statistics. */ + reordering_exit(); + quantile_exit(); + duplication_exit(); + + fclose(sf); + + exit(0); + } + + #endif /* THRULAY_REPORTING_SAMPLE_LOOP */ + +Appendix B. Example Report + + This appendix only serves for illustrative purposes. + + This report is produced by running the sample program in Appendix A + on the sample input embedded in a comment in its source code: + + Delay: 109.000ms + Loss: 10.000% + Jitter: 40.000ms + Duplication: 18.182% + Reordering: 25.000% + +Appendix C. TODO + + FIXME: This section needs to be removed before publication. + + o Add references + +Appendix D. Revision History FIXME: This section needs to be removed before publication. $Log: draft-ietf-ippm-reporting.xml,v $ + Revision 1.8 2006/10/23 21:45:54 shalunov + draft-ietf-ippm-reporting-01.txt + + Revision 1.7 2006/10/23 21:45:13 shalunov + Add sample source code and output. + Revision 1.6 2006/06/02 21:21:57 shalunov draft-ietf-ippm-reporting-00: Include a ``Scope'' section. Change tags from draft-shalunov-ippm-reporting. Revision 1.5 2006/05/02 20:25:44 shalunov Version 03: Various refinements and clarifications based on feedback from Reza Fardid, Ruediger Geib, and Al Morton. Revision 1.4 2006/04/25 22:38:58 shalunov Version 02: Address comments from Carsten Schmoll, sent in message @@ -365,32 +1513,39 @@ Revision 1.3 2006/04/11 22:09:47 shalunov Version 01: Wording changes based on discussion with Matt Zekauskas (reordering, loss). Rewrite abstract a bit. Add TODO list. Revision 1.2 2006/04/04 21:39:20 shalunov Convert to xml2rfc 1.30 and RFC 3978 IPR statement. Revision 1.1.1.1 2006/04/02 17:07:36 shalunov Initial import into CVS. -Author's Address +Authors' Addresses Stanislav Shalunov Internet2 1000 Oakbrook Drive, Suite 300 Ann Arbor, MI 48104 US - Phone: +1-734-913-4260 Email: shalunov@internet2.edu URI: http://www.internet2.edu/~shalunov/ + Bernhard Lutzmann + + Email: belu@users.sf.net + + Federico Montesino Pouzols + + Email: fedemp@altern.org + Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79.