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Checking references for intended status: Proposed Standard ---------------------------------------------------------------------------- (See RFCs 3967 and 4897 for information about using normative references to lower-maturity documents in RFCs) == Unused Reference: 'Chabarek' is defined on line 639, but no explicit reference was found in the text == Outdated reference: A later version (-18) exists of draft-ietf-quic-applicability-01 ** Downref: Normative reference to an Informational draft: draft-ietf-quic-applicability (ref. 'I-D.ietf-quic-applicability') ** Downref: Normative reference to an Historic RFC: RFC 1692 Summary: 2 errors (**), 0 flaws (~~), 3 warnings (==), 1 comment (--). Run idnits with the --verbose option for more detailed information about the items above. -------------------------------------------------------------------------------- 2 Transport Area Working Group J. Saldana 3 Internet-Draft J. Fernandez Navajas 4 Intended status: Standards Track J. Ruiz Mas 5 Expires: September 3, 2018 University of Zaragoza 6 March 2, 2018 8 Simplemux. A generic multiplexing protocol 9 draft-saldana-tsvwg-simplemux-09 11 Abstract 13 The high amount of small packets present in nowaday's networks 14 results in a low efficiency, as the size of the headers and the 15 payload of these packets can be in the same order of magnitude. In 16 some situations, multiplexing a number of small packets into a bigger 17 one is desirable in order to improve the efficiency. For example, a 18 number of small packets can be sent together between a pair of 19 machines if they share a common network path. Thus, the traffic 20 profile can be shifted from small to larger packets, reducing the 21 network overhead and the number of packets per second to be managed 22 by intermediate routers. 24 This document describes Simplemux, a protocol able to encapsulate a 25 number of packets belonging to different protocols into a single 26 packet. Small headers (separators) are added at the beginning of 27 each multiplexed packet, including some flags, the packet length and 28 a "Protocol" field. This allows the inclusion of a number of packets 29 belonging to different protocols (the "multiplexed packets") on a 30 packet of another protocol (the "tunneling protocol"). 32 In order to reduce the overhead, the size of the multiplexing headers 33 is kept very low (it may be a single byte when multiplexing small 34 packets). 36 Status of This Memo 38 This Internet-Draft is submitted to IETF in full conformance with the 39 provisions of BCP 78 and BCP 79. 41 Internet-Drafts are working documents of the Internet Engineering 42 Task Force (IETF). Note that other groups may also distribute 43 working documents as Internet-Drafts. The list of current Internet- 44 Drafts is at https://datatracker.ietf.org/drafts/current/. 46 Internet-Drafts are draft documents valid for a maximum of six months 47 and may be updated, replaced, or obsoleted by other documents at any 48 time. It is inappropriate to use Internet-Drafts as reference 49 material or to cite them other than as "work in progress." 51 This Internet-Draft will expire on September 3, 2018. 53 Copyright Notice 55 Copyright (c) 2018 IETF Trust and the persons identified as the 56 document authors. All rights reserved. 58 This document is subject to BCP 78 and the IETF Trust's Legal 59 Provisions Relating to IETF Documents 60 (https://trustee.ietf.org/license-info) in effect on the date of 61 publication of this document. Please review these documents 62 carefully, as they describe your rights and restrictions with respect 63 to this document. 65 Table of Contents 67 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 68 1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3 69 1.2. Existing multiplexing protocols . . . . . . . . . . . . . 3 70 1.3. Benefits of multiplexing . . . . . . . . . . . . . . . . 5 71 2. Description of the scenario . . . . . . . . . . . . . . . . . 6 72 3. Protocol description . . . . . . . . . . . . . . . . . . . . 6 73 4. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 74 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 75 6. Security Considerations . . . . . . . . . . . . . . . . . . . 13 76 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 13 77 7.1. Normative References . . . . . . . . . . . . . . . . . . 13 78 7.2. Informative References . . . . . . . . . . . . . . . . . 14 79 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 14 81 1. Introduction 83 The high amount of small packets present in nowaday's networks 84 results in a low efficiency, when the size of the headers and the 85 payload are in the same order of magnitude. In some situations, 86 multiplexing a number of small packets into a bigger one is desirable 87 in order to improve the efficiency. For example, a number of small 88 packets can be sent together between a pair of machines if they share 89 a common network path. Thus, the traffic profile can be shifted from 90 small to larger packets, thus reducing the network overhead and the 91 number of packets per second to be managed by intermediate routers. 93 This document describes Simplemux, a protocol able to encapsulate a 94 number of packets belonging to different protocols into a single 95 packet. This can be useful e.g. for grouping small packets and thus 96 reducing the number of packets per second in a network. 98 Simplemux is a generic multiplexing protocol, i.e. it can be used to 99 aggregate a number of packets belonging to a protocol, on a single 100 packet belonging to other (or the same) protocol. One example of 101 this is the fallback from QUIC to TLS over TCP 102 [I-D.ietf-quic-applicability], which requires stream multiplexing. 103 This is not provided by TCP, and could be implemented in other 104 layers. 106 In this document we will talk about the "multiplexed" protocol, and 107 the "tunneling" protocol, being Simplemux the "multiplexing" 108 protocol. The "external header" will be the one of the "tunneling" 109 protocol (see the figure (Figure 1)) 111 +--------------------------------+ 112 | Multiplexed Packet | Multiplexed protocol 113 +--------------------------------+ 114 | Simplemux | Multiplexing protocol 115 +--------------------------------+ 116 | Tunneling header | Tunneling protocol 117 +--------------------------------+ 119 Figure 1 121 As an example, if a number of small IPv6 packets have to travel over 122 an IPv4 network, they can be multiplexed and put into a single IPv4 123 packet. In this case, IPv4 is the "tunneling" protocol and IPv6 is 124 the "multiplexed" protocol. The IPv4 header is called in this case 125 the "tunneling" or the "external" header. The simplified scheme of 126 this packet would be: 128 |IPv4 hdr||Simplemux hdr|IPv6 packet||Simplemux hdr|IPv6 packet||...| 130 1.1. Requirements Language 132 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", 133 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this 134 document are to be interpreted as described in RFC 2119 [RFC2119]. 136 1.2. Existing multiplexing protocols 138 Different multiplexing protocols have been approved by the IETF in 139 the past: 141 o TMux [RFC1692] 143 TMux is able to combine multiple short transport segments, 144 independent of application type, and send them between a server and 145 host pair. As stated in the reference, "The TMux protocol is 146 intended to optimize the transmission of large numbers of small data 147 packets. In particular, communication load is not measured only in 148 bits per seconds but also in packets per seconds, and in many 149 situation the latter is the true performance limit, not the former. 150 The proposed multiplexing is aimed at alleviating this situation." 152 A TMux message appears as: 154 |IP hdr||TMux hdr|Transport segment||TMux hdr|Transport segment||...| 156 Therefore, the Transport Segment is not an entire IP packet, since it 157 does not include the IP header. 159 TMux works "between a server and host pair," so it multiplexes a 160 number of segments between the same pair of machines. However, there 161 are scenarios where a number of low-efficiency flows share a common 162 path, but they do not travel between the same pair of machines. 164 o PPPMux [RFC3153] 166 PPPMux "sends multiple PPP encapsulated packets in a single PPP 167 frame. As a result, the PPP overhead per packet is reduced." Thus, 168 it is able to multiplex complete IP packets, using separators. 170 However, the use of PPPMux requires the use of PPP and L2TP in order 171 to multiplex a number of packets together, as done in TCRTP 172 [RFC4170]. Thus, it introduces more overhead and complexity. 174 An IP packet including a number of them using PPPMux appears as: 176 |IP hdr|L2TP hdr|PPP hdr||PPPMux hdr|packet||PPPMux hdr|packet||...| 178 The scheme proposed by PPPMux is similar to the Compound-Frames of 179 PPP LCP Extensions [RFC1570]. The key differences are that PPPMux is 180 more efficient and that it allows concatenation of variable sized 181 frames. 183 *** 185 The definition of a protocol able to multiplex complete packets, 186 avoiding the need of other protocols as PPP is seen as convenient. 187 The multiplexed packets can be of any kind, since a "Protocol Number" 188 field can be added to each of them. Not all the packets multiplexed 189 together must belong to the same protocol. The general scheme of 190 Simplemux is: 192 |tunnel hdr||Simplemux hdr|packet||Simplemux hdr|packet||...| 194 The Simplemux header includes the "Protocol Number" field, so it 195 permits the multiplexing of different kinds of packets in the same 196 bundle. 198 We will also refer to the Simplemux header with the terms 199 "separator," "Simplemux separator" or "mux separator". In the 200 figures we will also use the abbreviation "Smux". 202 When applied to IP packets, the scheme of a multiplexed packet 203 becomes: 205 |tunnel hdr||Simplemux hdr|IP packet||Simplemux hdr|IP packet||...| 207 1.3. Benefits of multiplexing 209 The benefits of multiplexing are: 211 - Tunneling a number of packets together. If a number of packets 212 have to be tunneled through a network segment, they can be 213 multiplexed and then sent together using a single external header. 214 This will avoid the need for adding a tunneling header to each of the 215 packets, thus reducing the overhead. 217 - Reduction of the amount of packets per second in the network. It 218 is desirable for two main reasons: first, network equipment has a 219 limitation in terms of the number of packets per second it can 220 manage, i.e. many devices are not able to send small packets back to 221 back due to processing delay. 223 - Bandwidth reduction. The presence of high rates of tiny packets 224 translates into an inefficient usage of network resources, so there 225 is a need for mechanisms able to reduce the overhead introduced by 226 low-efficiency flows. When combined with header compression, as done 227 in TCRTP [RFC4170] multiplexing may produce significant bandwidth 228 savings, which are interesting for network operators, since they may 229 alleviate the traffic load in their networks. 231 - Energy savings: a lower amount of packets per second will reduce 232 energy consumption in network equipment since, according to [Bolla], 233 internal packet processing engines and switching fabric require 60% 234 and 18% of the power consumption of high-end routers respectively. 235 Thus, reducing the number of packets to be managed and switched will 236 reduce the overall energy consumption. The measurements deployed in 238 [Chabarek]on commercial routers corroborate this. A study using 239 different packet sizes was presented, and the tests with big packets 240 showed that energy consumption gets reduced, since a non-negligible 241 amount of energy is associated to header processing tasks, and not 242 only to the sending of the packet itself. 244 2. Description of the scenario 246 Simplemux works between a pair of machines. It creates a tunnel 247 between an "ingress" and an "egress". They MAY be the endpoints of 248 the communication, but they MAY also be middleboxes able to multiplex 249 packets belonging to different flows. Different mechanisms MAY be 250 used in order to classify flows according to some criteria (sharing a 251 common path, kind of service, etc.) and to select the flows to be 252 multiplexed and sent to the egress (see Figure 2). 254 +-------+ 255 | | +---------+ +---------+ 256 | | ---> |Simplemux| _ _ |Simplemux| --> 257 |classif| ---> | ingress | ===> ( ` )_ ===> | egress | --> 258 | | +---------+ ( Network `) +---------+ 259 | | --------------------> (_ (_ . _) _) -----------------> 260 +-------+ 261 <--------Simplemux--------> 263 Figure 2 265 3. Protocol description 267 A Simplemux packet consists of: 269 - An external header that is used as the tunneling header for the 270 whole packet. 272 - A series of pairs "Simplemux header" + "packet" of the multiplexed 273 protocol. 275 This is the scheme of a Simplemux packet: 277 |tun hdr||Simplemux hdr|packet||Simplemux hdr|packet||...| 279 The Simplemux header has two different forms: one for the "First 280 Simplemux header," and another one for the rest of the Simplemux 281 headers (called "Non-first Simplemux headers"): 283 o First Simplemux header (after the tunneling header, and before the 284 first multiplexed packet): 286 In order to allow the multiplexing of packets of any length, the 287 number of bytes expressing the length is variable, and a field called 288 "Length Extension" (LXT, one bit) is used to flag if the current byte 289 is the last one including length information. This is the structure 290 of a First Simplemux header: 292 |SPB(1 bit)|LXT(1 bit)|length (6 bits)||LXT(1 bit)|length (7 293 bits)||...||Protocol (8 bits)| 295 - Single Protocol Bit (SPB, one bit) only appears in the first 296 Simplemux header. It is set to 1 if all the multiplexed packets 297 belong to the same protocol (in this case, the "Protocol" field will 298 only appear in the first Simplemux header). It is set to 0 when each 299 packet MAY belong to a different protocol. 301 - Length Extension (LXT, one bit) is 0 if the current byte is the 302 last byte where the length of the first packet is included, and 1 in 303 other case. 305 - Length (LEN, 6, 13, 20, etc. bits): This is the length of the 306 multiplexed packet (in bytes), not including the length field. If 307 the length of the multiplexed packet is less than 64 bytes (less than 308 or equal to 63 bytes), the first LXT is set to 0 and the 6 bits of 309 the length field are the length of the multiplexed packet. If the 310 length of the multiplexed packet is equal or greater than 64 bytes, 311 additional bytes are added. The first bit of each of the added bytes 312 is the LXT. If LXT is set to 1, it means that there is an additional 313 byte for expressing the length. This allows to multiplex packets of 314 any length (see the next figures). 316 - Protocol (8 bits) is the Protocol field of the multiplexed packet, 317 according to IANA "Assigned Internet Protocol Numbers." 319 As an example, a First Simplemux header before a packet smaller than 320 64 (2^6) bytes would be 2 bytes long: 322 0 1 323 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 324 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 325 |S|L| | | 326 |P|X| Length | Protocol | 327 |B|T| (6 bits) | (8 bits) | 328 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 329 ^ 330 0 332 Figure 3 334 A First Simplemux header before a packet with a length greater or 335 equal to 64 bytes, and smaller than 8192 bytes (2^13) will be 3 bytes 336 long: 338 0 1 2 339 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 340 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 341 |S|L| |L| | | 342 |P|X| Length 1 |X| Length 2 | Protocol | 343 |B|T| (6 bits) |T| (7 bits) | (8 bits) | 344 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 345 ^ ^ 346 1 0 348 Figure 4 350 In this case, the length of the packet will be the number expressed 351 by the concatenation of the bits of Length 1 - Length 2 (total 13 352 bits). Length 1 includes the 6 most significant bits and Length 2 353 the 7 less significant bits. 355 A First Simplemux header before a packet with a length greater of 356 equal to 8192 bytes, and smaller than 1048576 bytes (2^20) would be 4 357 bytes long: 359 0 1 2 3 360 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 361 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 362 |S|L| |L| |L| | | 363 |P|X| Length 1 |X| Length 2 |X| Length 3 | Protocol | 364 |B|T| (6 bits) |T| (7 bits) |T| (7 bits) | (8 bits) | 365 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 366 ^ ^ ^ 367 1 1 0 369 Figure 5 371 In this case, the length of the packet will be the number expressed 372 by the concatenation of the bits of Length 1 - Length 2 - Length 3 373 (total 20 bits). Length 1 includes the 6 most significant bits and 374 Length 3 the less 7 significant bits. 376 More bytes can be added to the length if required, using the same 377 scheme: 1 LXT byte plus 7 bits for expressing the length. 379 o Subsequent (Non-first) Simplemux headers (before the other 380 packets): 382 The Non-first Simplemux headers also employ a format allowing the 383 multiplexing of packets of any length, so the number of bytes 384 expressing the length is variable, and the field Length Extension 385 (LXT, one bit) is used to flag if the current byte is the last one 386 including length information. This is the structure of a Non-first 387 Simplemux header: 389 |LXT(1 bit)|length (7 bits)||LXT(1 bit)|length (7 390 bits)||...||Protocol (8 bits, optional)| 392 - Length Extension (LXT, one bit) is 0 if the current byte is the 393 last byte where the length of the packet is included, and 1 in other 394 case. 396 - Length (LEN, 7, 14, 21, etc. bits): This is the length of the 397 multiplexed packet (in bytes), not including the length field. If 398 the length of the multiplexed packet is less than 128 bytes (less 399 than or equal to 127 bytes), LXT is set to 0 and the 7 bits of the 400 length field represent the length of the multiplexed packet. If the 401 length of the multiplexed packet is greater than 127 bytes, 402 additional bytes are added. The first bit of each of the added bytes 403 is the LXT. If LXT is set to 1, it means that there is an additional 404 byte for expressing the length. This allows to multiplex packets of 405 any length (see the next figures). 407 - Protocol (8 bits) is the Protocol field of the multiplexed packet, 408 according to IANA "Assigned Internet Protocol Numbers". It only 409 appears in Non-first headers if the Single Protocol Bit (SPB) of the 410 First Simplemux header is set to 1. 412 As an example, a Non-first Simplemux header before a packet smaller 413 than 128 bytes, when the protocol bit has been set to 0 in the first 414 header, would be 1 byte long: 416 0 417 0 1 2 3 4 5 6 7 418 +-+-+-+-+-+-+-+-+ 419 |L| | 420 |X| Length | 421 |T| (7 bits) | 422 +-+-+-+-+-+-+-+-+ 423 ^ 424 0 426 SPB = 0 in the first header 428 Figure 6 430 A Non-first Simplemux header before a packet witha a length greater 431 or equal to 128 bytes, and smaller than 16384 (2^14), when the 432 protocol bit has been set to 0 in the first header, will be 2 bytes 433 long: 435 0 1 436 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 437 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 438 |L| |L| | 439 |X| Length 1 |X| Length 2 | 440 |T| (7 bits) |T| (7 bits) | 441 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 442 ^ ^ 443 1 0 445 SPB = 0 in the first header 447 Figure 7 449 A Non-first Simplemux header before a packet with a length greater or 450 equal to 16384 bytes, and smaller than 2097152 bytes (2^21), when the 451 protocol bit has been set to 0 in the first header, will be 3 bytes 452 long: 454 0 1 2 455 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 456 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 457 |L| |L| |L| | 458 |X| Length 1 |X| Length 2 |X| Length 3 | 459 |T| (7 bits) |T| (7 bits) |T| (7 bits) | 460 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 461 ^ ^ ^ 462 1 1 0 464 SPB = 0 in the first header 466 Figure 8 468 In this case, the length of the packet will be the number expressed 469 by the concatenation of the bits of Length 1 - Length 2 - Length 3 470 (total 21 bits). Length 1 includes the 7 most significant bits and 471 Length 3 the 7 less significant bits. 473 More bytes can be added to the length if required, using the same 474 scheme: 1 LXT byte plus 7 bits for expressing the length. 476 A Non-first Simplemux header before a packet smaller than 128 bytes, 477 when the protocol bit has been set to 1 in the first header, will be 478 2 bytes long: 480 0 1 481 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 482 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 483 |L| | | 484 |X| Length | Protocol | 485 |T| (7 bits) | (8 bits) | 486 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 487 ^ 488 0 490 SPB = 1 in the first header 492 Figure 9 494 A Non-first Simplemux header before a packet with a length greater or 495 equal to 128 bytes, and smaller than 16384 (2^14), when the protocol 496 bit has been set to 1 in the first header, will be 3 bytes long: 498 0 1 2 499 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 500 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 501 |L| |L| | | 502 |X| Length 1 |X| Length 2 | Protocol | 503 |T| (7 bits) |T| (7 bits) | (8 bits) | 504 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 505 ^ ^ 506 1 0 508 SPB = 1 in the first header 510 Figure 10 512 A Non-first Simplemux header before a packet with a length greater of 513 equal to 16384 bytes, and smaller than 2097152 bytes (2^21), when the 514 protocol bit has been set to 1 in the first header, will be 4 bytes 515 long: 517 0 1 2 3 518 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 519 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 520 |L| |L| |L| | | 521 |X| Length 1 |X| Length 2 |X| Length 3 | Protocol | 522 |T| (7 bits) |T| (7 bits) |T| (7 bits) | (8 bits) | 523 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 524 ^ ^ ^ 525 1 1 0 527 SPB = 1 in the first header 529 Figure 11 531 In this case, the length of the packet will be the number expressed 532 by the concatenation of the bits of Length 1 - Length 2 - Length 3 533 (total 21 bits). Length 1 includes the 7 most significant bits and 534 Length 3 the 7 less significant bits. 536 More bytes can be added to the length if required, using the same 537 scheme: 1 LXT byte plus 7 bits for expressing the length. 539 These would be some examples of the whole bundles: 541 Case 1: All the packets belong to the same protocol: The first 542 Simplemux header would be 2 or 3 bytes (for usual packet sizes), and 543 the other Simplemux headers would be 1 or 2 bytes. For small packets 544 (< 128 bytes), the Simplemux header would only require one byte. 546 |tun||1|0|len|Protocol|pkt||0|len|pkt||1|len|0|len|pkt||...| 547 | | | | 548 v v v v 549 (6 bits) (7 bits) (14 bits) 551 |tun||1|1|len|0|len|Protocol|pkt||0|len|pkt||1|len|0|len|pkt||...| 552 | | | | | 553 v v v v v 554 (13 bits) (7 bits) (14 bits) 556 Figure 12 558 Case 2: Each packet may belong to a different protocol: All the 559 Simplemux headers would be 2 or 3 bytes (for usual packet sizes). 561 |tun||0|0|len|Prot|pkt||0|len|Prot|pkt||1|len|0|len|Prot|pkt||...| 562 | | | | 563 v v v v 564 (6 bits) (7 bits) (14 bits) 566 |tun||0|1|len|0|len|Prot|pkt||0|len|Prot|pkt||1|len|0|len|Prot|pkt||...| 567 | | | | | 568 v v v v v 569 (13 bits) (7 bits) (14 bits) 571 Figure 13 573 4. Acknowledgements 575 This work has been partially funded by the EU H2020 Wi-5 project 576 (Grant Agreement no: 644262) and the Spanish Ministry of Economy and 577 Competitiveness project TIN2015-64770-R, in cooperation with the 578 European Regional Development Fund. 580 5. IANA Considerations 582 A protocol number for Simplemux should be requested to IANA. 584 As a provisional solution for IP networks, the ingress and the egress 585 optimizers may agree on a UDP port, and use IP/UDP as the 586 multiplexing protocol. 588 6. Security Considerations 590 Simplemux protocol has been developed in such a way that packet 591 aggregation and security can be simultaneously applied to the same 592 traffic flows, i.e. a single security header could protect a number 593 of packets belonging to different flows. 595 As a consequence, the overall efficiency could be improved, as the 596 number of security headers could be reduced from N (being N the 597 number of multiplexed packets) to 1. 599 7. References 601 7.1. Normative References 603 [I-D.ietf-quic-applicability] 604 Kuehlewind, M. and B. Trammell, "Applicability of the QUIC 605 Transport Protocol", draft-ietf-quic-applicability-01 606 (work in progress), October 2017. 608 [RFC1570] Simpson, W., Ed., "PPP LCP Extensions", RFC 1570, 609 DOI 10.17487/RFC1570, January 1994, 610 . 612 [RFC1692] Cameron, P., Crocker, D., Cohen, D., and J. Postel, 613 "Transport Multiplexing Protocol (TMux)", RFC 1692, 614 DOI 10.17487/RFC1692, August 1994, 615 . 617 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate 618 Requirement Levels", BCP 14, RFC 2119, 619 DOI 10.17487/RFC2119, March 1997, 620 . 622 [RFC3153] Pazhyannur, R., Ali, I., and C. Fox, "PPP Multiplexing", 623 RFC 3153, DOI 10.17487/RFC3153, August 2001, 624 . 626 [RFC4170] Thompson, B., Koren, T., and D. Wing, "Tunneling 627 Multiplexed Compressed RTP (TCRTP)", BCP 110, RFC 4170, 628 DOI 10.17487/RFC4170, November 2005, 629 . 631 7.2. Informative References 633 [Bolla] Bolla, R., Bruschi, R., Davoli, F., and F. Cucchietti, 634 "Energy Efficiency in the Future Internet: A Survey of 635 Existing Approaches and Trends in Energy-Aware Fixed 636 Network Infrastructures", IEEE Communications Surveys and 637 Tutorials vol.13, no.2, pp.223,244, 2011. 639 [Chabarek] 640 Chabarek, J., Sommers, J., Barford, P., Estan, C., Tsiang, 641 D., and S. Wright, "Power Awareness in Network Design and 642 Routing", INFOCOM 2008. The 27th Conference on Computer 643 Communications. IEEE pp.457,465, 2008. 645 Authors' Addresses 647 Jose Saldana 648 University of Zaragoza 649 Dpt. IEC Ada Byron Building 650 Zaragoza 50018 651 Spain 653 Phone: +34 976 762 698 654 Email: jsaldana@unizar.es 655 Julian Fernandez Navajas 656 University of Zaragoza 657 Dpt. IEC Ada Byron Building 658 Zaragoza 50018 659 Spain 661 Phone: +34 976 761 963 662 Email: navajas@unizar.es 664 Jose Ruiz Mas 665 University of Zaragoza 666 Dpt. IEC Ada Byron Building 667 Zaragoza 50018 668 Spain 670 Phone: +34 976 762 158 671 Email: jruiz@unizar.es