summaryrefslogtreecommitdiff
path: root/papers/draft-gsenger-secure-anycast-tunneling-protocol-02.html
blob: 80ab6c94db5435b16ae422521c963686c74ab315 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html lang="en"><head><title>secure anycast tunneling protocol (SATP)</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="description" content="secure anycast tunneling protocol (SATP)">
<meta name="keywords" content="satp, Internet-Draft, secure anycast tunneling protocol, anycast, tunnel, secure, protocol">
<meta name="generator" content="xml2rfc v1.31 (http://xml.resource.org/)">
<style type='text/css'><!--
	body {
		font-family: verdana, charcoal, helvetica, arial, sans-serif;
		font-size: small; color: #000; background-color: #FFF;
		margin: 2em;
	}
        h1, h2, h3, h4, h5, h6 {
		font-family: helvetica, monaco, "MS Sans Serif", arial, sans-serif;
		font-weight: bold; font-style: normal;
	}
	h1 { color: #900; background-color: transparent; text-align: right; }
	h3 { color: #333; background-color: transparent; }

	td.RFCbug {
		font-size: x-small; text-decoration: none;
		width: 30px; height: 30px; padding-top: 2px;
		text-align: justify; vertical-align: middle;
		background-color: #000;
	}
	td.RFCbug span.RFC {
		font-family: monaco, charcoal, geneva, "MS Sans Serif", helvetica, verdana, sans-serif;
		font-weight: bold; color: #666;
	}
	td.RFCbug span.hotText {
		font-family: charcoal, monaco, geneva, "MS Sans Serif", helvetica, verdana, sans-serif;
		font-weight: normal; text-align: center; color: #FFF;
	}

	table.TOCbug { width: 30px; height: 15px; }
	td.TOCbug {
		text-align: center; width: 30px; height: 15px;
		color: #FFF; background-color: #900;
	}
	td.TOCbug a {
		font-family: monaco, charcoal, geneva, "MS Sans Serif", helvetica, sans-serif;
		font-weight: bold; font-size: x-small; text-decoration: none;
		color: #FFF; background-color: transparent;
	}

	td.header {
		font-family: arial, helvetica, sans-serif; font-size: x-small;
		vertical-align: top; width: 33%;
		color: #FFF; background-color: #666;
	}
	td.author { font-weight: bold; font-size: x-small; margin-left: 4em; }
	td.author-text { font-size: x-small; }

	/* info code from SantaKlauss at http://www.madaboutstyle.com/tooltip2.html */
	a.info {
		/* This is the key. */
		position: relative;
		z-index: 24;
		text-decoration: none;
	}
	a.info:hover {
		z-index: 25;
		color: #FFF; background-color: #900;
	}
	a.info span { display: none; }
	a.info:hover span.info {
		/* The span will display just on :hover state. */
		display: block;
		position: absolute;
		font-size: smaller;
		top: 2em; left: -5em; width: 15em;
		padding: 2px; border: 1px solid #333;
		color: #900; background-color: #EEE;
		text-align: left;
	}

	a { font-weight: bold; }
	a:link    { color: #900; background-color: transparent; }
	a:visited { color: #633; background-color: transparent; }
	a:active  { color: #633; background-color: transparent; }

	p { margin-left: 2em; margin-right: 2em; }
	p.copyright { font-size: x-small; }
	p.toc { font-size: small; font-weight: bold; margin-left: 3em; }
	table.toc { margin: 0 0 0 3em; padding: 0; border: 0; vertical-align: text-top; }
	td.toc { font-size: small; font-weight: bold; vertical-align: text-top; }

	ol.text { margin-left: 2em; margin-right: 2em; }
	ul.text { margin-left: 2em; margin-right: 2em; }
	li      { margin-left: 3em; }

	/* RFC-2629 <spanx>s and <artwork>s. */
	em     { font-style: italic; }
	strong { font-weight: bold; }
	dfn    { font-weight: bold; font-style: normal; }
	cite   { font-weight: normal; font-style: normal; }
	tt     { color: #036; }
        tt, pre, pre dfn, pre em, pre cite, pre span {
		font-family: "Courier New", Courier, monospace; font-size: small;
	}
	pre {
		text-align: left; padding: 4px;
		color: #000; background-color: #CCC;
	}
	pre dfn  { color: #900; }
	pre em   { color: #66F; background-color: #FFC; font-weight: normal; }
	pre .key { color: #33C; font-weight: bold; }
	pre .id  { color: #900; }
	pre .str { color: #000; background-color: #CFF; }
	pre .val { color: #066; }
	pre .rep { color: #909; }
	pre .oth { color: #000; background-color: #FCF; }
	pre .err { background-color: #FCC; }

	/* RFC-2629 <texttable>s. */
	table.full, table.headers, table.none {
		font-size: small; text-align: center; border-width: 2px;
		vertical-align: top; border-collapse: collapse;
	}
	table.full { border-style: solid; border-color: black; }
	table.headers, table.none { border-style: none; }
	th {
		font-weight: bold; border-color: black;
		border-width: 2px 2px 3px 2px;
	}
	table.full th { border-style: solid; }
	table.headers th { border-style: none none solid none; }
	table.none th { border-style: none; }
	table.full td {
		border-style: solid; border-color: #333;
		border-width: 1px 2px;
	}
	table.headers td, table.none td { border-style: none; }

	hr { height: 1px; }
	hr.insert {
		width: 80%; border-style: none; border-width: 0;
		color: #CCC; background-color: #CCC;
	}
--></style>
</head>
<body>
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<table summary="layout" width="66%" border="0" cellpadding="0" cellspacing="0"><tr><td><table summary="layout" width="100%" border="0" cellpadding="2" cellspacing="1">
<tr><td class="header">Network Working Group</td><td class="header">O. Gsenger</td></tr>
<tr><td class="header">Internet-Draft</td><td class="header">January 2008</td></tr>
<tr><td class="header">Intended status: Informational</td><td class="header">&nbsp;</td></tr>
<tr><td class="header">Expires: July 4, 2008</td><td class="header">&nbsp;</td></tr>
</table></td></tr></table>
<h1><br />secure anycast tunneling protocol (SATP)<br />draft-gsenger-secure-anycast-tunneling-protocol-01</h1>

<h3>Status of this Memo</h3>
<p>
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&nbsp;6 of BCP&nbsp;79.</p>
<p>
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups.
Note that other groups may also distribute working documents as
Internet-Drafts.</p>
<p>
Internet-Drafts are draft documents valid for a maximum of six months
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 &ldquo;work in progress.&rdquo;</p>
<p>
The list of current Internet-Drafts can be accessed at
<a href='http://www.ietf.org/ietf/1id-abstracts.txt'>http://www.ietf.org/ietf/1id-abstracts.txt</a>.</p>
<p>
The list of Internet-Draft Shadow Directories can be accessed at
<a href='http://www.ietf.org/shadow.html'>http://www.ietf.org/shadow.html</a>.</p>
<p>
This Internet-Draft will expire on July 4, 2008.</p>

<h3>Copyright Notice</h3>
<p>
Copyright &copy; The Internet Society (2008).</p>

<h3>Abstract</h3>

<p>The secure anycast tunneling protocol (SATP) defines a protocol used for communication between any combination of unicast and anycast tunnel endpoints. It allows tunneling of every ETHER TYPE protocol (ethernet, ip ...). SATP directly includes cryptography and message authentication based on the methodes used by SRTP. It can be used as an encrypted alternative to <a class='info' href='#RFC2003'>IP Encapsulation within IP<span> (</span><span class='info'>Perkins, C., &ldquo;IP Encapsulation within IP,&rdquo; October&nbsp;1996.</span><span>)</span></a> [3] and <a class='info' href='#RFC2784'>Generic Routing Encapsulation (GRE)<span> (</span><span class='info'>Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. Traina, &ldquo;Generic Routing Encapsulation (GRE),&rdquo; March&nbsp;2000.</span><span>)</span></a> [4]. It supports both anycast receivers and senders.
            
</p><a name="toc"></a><br /><hr />
<h3>Table of Contents</h3>
<p class="toc">
<a href="#anchor1">1.</a>&nbsp;
Introduction<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor2">1.1.</a>&nbsp;
Notational Conventions<br />
<a href="#anchor3">2.</a>&nbsp;
Motivation and usage scenarios<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor4">2.1.</a>&nbsp;
Usage scenarions<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor5">2.1.1.</a>&nbsp;
Tunneling from unicast hosts over anycast routers to other unicast hosts<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor6">2.1.2.</a>&nbsp;
Tunneling from unicast hosts to anycast networks<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor7">2.1.3.</a>&nbsp;
Redundant tunnel connection of 2 networks<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor8">2.2.</a>&nbsp;
Encapsulation<br />
<a href="#anchor9">3.</a>&nbsp;
Using SATP on top of IP<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor10">3.1.</a>&nbsp;
Fragmentation<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor11">3.2.</a>&nbsp;
ICMP messages<br />
<a href="#anchor12">4.</a>&nbsp;
Protocol specification<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor13">4.1.</a>&nbsp;
Header format<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor14">4.2.</a>&nbsp;
sequence number<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor15">4.3.</a>&nbsp;
sender ID<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor16">4.4.</a>&nbsp;
MUX<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor17">4.5.</a>&nbsp;
payload type field<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor18">4.6.</a>&nbsp;
payload<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor19">4.7.</a>&nbsp;
padding (OPTIONAL)<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor20">4.8.</a>&nbsp;
padding count (OPTIONAL)<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor21">4.9.</a>&nbsp;
MKI (OPTIONAL)<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor22">4.10.</a>&nbsp;
authentication tag (RECOMMENDED)<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor23">4.11.</a>&nbsp;
Encryption<br />
<a href="#anchor24">5.</a>&nbsp;
Security Considerations<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#anchor25">5.1.</a>&nbsp;
Replay protection<br />
<a href="#anchor26">6.</a>&nbsp;
IANA Considerations<br />
<a href="#rfc.references1">7.</a>&nbsp;
References<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#rfc.references1">7.1.</a>&nbsp;
Normative References<br />
&nbsp;&nbsp;&nbsp;&nbsp;<a href="#rfc.references2">7.2.</a>&nbsp;
Informational References<br />
<a href="#rfc.authors">&#167;</a>&nbsp;
Author's Address<br />
<a href="#rfc.copyright">&#167;</a>&nbsp;
Intellectual Property and Copyright Statements<br />
</p>
<br clear="all" />

<a name="anchor1"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.1"></a><h3>1.&nbsp;
Introduction</h3>

<p>SATP is a mixture of a generic encapsulation protocol like <a class='info' href='#RFC2784'>GRE<span> (</span><span class='info'>Farinacci, D., Li, T., Hanks, S., Meyer, D., and P. Traina, &ldquo;Generic Routing Encapsulation (GRE),&rdquo; March&nbsp;2000.</span><span>)</span></a> [4] and a secure tunneling protocol as <a class='info' href='#RFC2401'>IPsec<span> (</span><span class='info'>Kent, S. and R. Atkinson, &ldquo;Security Architecture for the Internet Protocol,&rdquo; November&nbsp;1998.</span><span>)</span></a> [5] in tunnel mode.  It can be used to build redundant virtual private network (VPN) connections.  It supports peer to peer tunnels, where tunnel endpoints can be any combination of unicast, multicast or anycast hosts, so it defines a <a class='info' href='#RFC1546'>Host Anycast Service<span> (</span><span class='info'>Partridge, C., Mendez, T., and W. Milliken, &ldquo;Host Anycasting Service,&rdquo; November&nbsp;1993.</span><span>)</span></a> [6]. Encryption is done per packet, so the protocol is robust against packet loss and routing changes.
				To save some header overhead it uses the encryption techniques of <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1]. 
				
</p>
<a name="anchor2"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.1.1"></a><h3>1.1.&nbsp;
Notational Conventions</h3>

<p>The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in  <a class='info' href='#RFC2119'>RFC2119<span> (</span><span class='info'>Bradner, S., &ldquo;Key words for use in RFCs to Indicate Requirement Levels,&rdquo; March&nbsp;1997.</span><span>)</span></a> [2].
</p>
<a name="anchor3"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2"></a><h3>2.&nbsp;
Motivation and usage scenarios</h3>

<p>This section gives an overview of possible usage scenarios. Please note, that the protocols used in the figures are only examples and that SATP itself does not care about either transport protocols or encapsulated protocols. Routing is not done by SATP and each implemetation MAY choose it's own way of doing this task (e.g. using functions provided by the operating system). SATP is used only to encapsulate and encrypt data.
</p>
<a name="anchor4"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2.1"></a><h3>2.1.&nbsp;
Usage scenarions</h3>

<a name="anchor5"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2.1.1"></a><h3>2.1.1.&nbsp;
Tunneling from unicast hosts over anycast routers to other unicast hosts</h3>
<br /><hr class="insert" />
<a name="tunnel_mode"></a>

<p>An example of SATP used to tunnel in a unicast client - anycast server model
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
                    --------- router -----------
                   /                            \
    unicast ------+---------- router ------------+------ unicast
    host           \                            /        host
                    --------- router -----------

  unicast  | encrypted     |  anycast  | encrypted     |  unicast
  tunnel   | communication |  tunnel   | communication |  tunnel
  endpoint | using SATP    |  endpoint | using SATP    |  endpoint
</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;1&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<p>In this scenario the payload gets encapsuleted into a SATP packet by a unicast host and gets transmitted to one of the anycast routers. It than gets decapsulated by the router. This router makes a routing descision based on the underlying protocol and transmits a new SATP package to one or more unicast hosts depending on the routing decision.
</p>
<a name="anchor6"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2.1.2"></a><h3>2.1.2.&nbsp;
Tunneling from unicast hosts to anycast networks</h3>
<br /><hr class="insert" />
<a name="open_tunnel_mode"></a>

<p>An example of SATP used to encrypt data between a unicast host and anycast networks
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
                       -------Router -+---- DNS Server
                      /                \
                     /                  --- 6to4 Router
                    /
    unicast -------+----------Router --+--- DNS Server
    host            \                   \
                     \                   --- 6to4 Router
                      \
                       -------Router -+---- DNS Server
                                       \
                                        --- 6to4 Router

  unicast  | encrypted     |  anycast  | plaintext
  tunnel   | communication |  tunnel   | anycast
  endpoint | using SATP    |  endpoint | services

</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;2&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<p>When the unicast hosts wants to transmit data to one of the anycast DNS servers, it encapsulates the data and sends a SATP packet to the anycast address of the routers. The packet arrives at one of the routers, gets decapsulated and routed to the DNS server. This method can be used to tunnel between a clients and networks providing anycast services. It can also be used the other way to virtually locate a unicast service within anycasted networks.
</p>
<a name="anchor7"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2.1.3"></a><h3>2.1.3.&nbsp;
Redundant tunnel connection of 2 networks</h3>
<br /><hr class="insert" />
<a name="connect_networks"></a>

<p>An example of SATP used to connect 2 networks
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
              Router -----------   ---------------Router
            /                   \ /                     \
    Network - Router ------------x                       Network
       A    \                   / \                     /   B
              Router -----------   ---------------Router

            | packets       |  packets  |  packets      |
 plaintext  | get           |  take a   |  get          | plaintext
 packets    | de/encrypted  |  random   |  de/encrypted | packets
            |de/encapsulated|   path    |de/encapsulated|

</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;3&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<p>Network A has multiple routers, that act as gateway/tunnel endpoints to another network B. This is done to build a redundant encrypted tunnel connection between the two networks. All tunnel endpoints of network A share the same anycast address and all tunnel endpoints of network B share another anycast address. When a packet from network A gets transmitted to network B, it first arrives on one of network A's border routers. Which router is used is determined by network A's internal routing. This router encapsulates the package and sends it to the anycast address of the network B routers. The SATP packet arrives at one of network B's routers and gets decapsulated and routed to it's destination within network B.
</p>
<a name="anchor8"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.2.2"></a><h3>2.2.&nbsp;
Encapsulation</h3>

<p>SATP does not depend on which lower layer protocols is used, but this section gives an example of how packets could look like.
      
</p><br /><hr class="insert" />
<a name="transport_udp"></a>

<p>Examples of SATP used with different lower layer and payload protocols
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
    +------+-----+-------------------------------+
    |      |     |      +----------------+-----+ |
    | IPv6 | UDP | SATP | Ethernet 802.3 | ... | |
    |      |     |      +----------------+-----+ |
    +------+-----+-------------------------------+

Tunneling of Ethernet over UDP/IPv6

    +------+-----+---------------------------+
    |      |     |      +------+-----+-----+ |
    | IPv4 | UDP | SATP | IPv6 | UDP | RTP | |
    |      |     |      +------+-----+-----+ |
    +------+-----+---------------------------+

Tunneling of IPv6 over UDP/IPv4 with RTP payload

    +------+-------------------------------+
    |      |      +----------------+-----+ |
    | IPv6 | SATP | Ethernet 802.3 | ... | |
    |      |      +----------------+-----+ |
    +------+-------------------------------+

Tunneling of Ethernet over IPv6

    +------+---------------------------+
    |      |      +------+-----+-----+ |
    | IPv4 | SATP | IPv6 | UDP | RTP | |
    |      |      +------+-----+-----+ |
    +------+---------------------------+

Tunneling of IPv6 over IPv4 with RTP payload
</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;4&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<a name="anchor9"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.3"></a><h3>3.&nbsp;
Using SATP on top of IP</h3>

<a name="anchor10"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.3.1"></a><h3>3.1.&nbsp;
Fragmentation</h3>

<p>
           The only way of fully supporting fragmentation would be to synchronise fragments between all anycast servers. This is considered to be too much overhead, so there are two non perfect solutions for these problems. Either fragmentation HAS TO be disabled or if not all fragments arrive at the same server the ip datagramm HAS TO be discarded. As routing changes are not expected to occure very frequently, the encapsulated protocol can do a retransmission and all fragments will arrive at the new server. 
         
</p>
<p>If the payload type is IP and the ip headers's Don't Fragment (DF) bit is set, than the DF bit of the outer IP header HAS TO be set as well.
</p>
<a name="anchor11"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.3.2"></a><h3>3.2.&nbsp;
ICMP messages</h3>

<p>ICMP messages MUST be relayed according to <a class='info' href='#RFC2003'>rfc2003 section 4<span> (</span><span class='info'>Perkins, C., &ldquo;IP Encapsulation within IP,&rdquo; October&nbsp;1996.</span><span>)</span></a> [3]. This is needed for path MTU detection.
</p>
<a name="anchor12"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4"></a><h3>4.&nbsp;
Protocol specification</h3>

<a name="anchor13"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.1"></a><h3>4.1.&nbsp;
Header format</h3>
<br /><hr class="insert" />
<a name="prot_header_table"></a>

<p>Protocol Format
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
      0                   1                   2                   3
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                         sequence number                       | |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
     |           sender ID           |              MUX              | |
   +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+ |
   | |         payload type          |                               | |
   | +-------------------------------+                               | |
   | |              ....        payload        ...                   | |
   | |                               +-------------------------------+ |
   | |                               | padding (OPT) | pad count(OPT)| |
   +#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+#+-+
   | ~                          MKI (OPTIONAL)                       ~ |
   | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
   | :                 authentication tag (RECOMMENDED)              : |
   | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
   |                                                                   |
   +- Encrypted Portion                       Authenticated Portion ---+
</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;5&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<p>
</p>
<a name="anchor14"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.2"></a><h3>4.2.&nbsp;
sequence number</h3>

<p>The sequence number is a 32 bit unsigned integer in network byte order. It starts with a random value and is increased by 1 for every sent packet. After the maximum value, it starts over from 0. This overrun causes the ROC to be increased.
</p>
<a name="anchor15"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.3"></a><h3>4.3.&nbsp;
sender ID</h3>

<p>The sender ID is a 16 bit unsigned integer. It HAS TO be unique for every sender sharing the same anycast address
</p>
<a name="anchor16"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.4"></a><h3>4.4.&nbsp;
MUX</h3>

<p>The MUX (multiplex) field is a 16 bit unsigned integer. It is used to destinguish multible tunnel connections.
</p>
<a name="anchor17"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.5"></a><h3>4.5.&nbsp;
payload type field</h3>

<p>The payload type field defines the payload protocol. ETHER TYPE protocol numbers are used. <a href='http://www.iana.org/assignments/ethernet-numbers'>See IANA assigned ethernet numbers</a> . The values 0000-05DC are reserverd and MUST NOT be used. 
        <br /><hr class="insert" />
<a name="prot_type_table"></a>

<p>Some examples for protocol types
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
HEX
0000 Reserved
.... Reserved
05DC Reserved
0800 Internet IP (IPv4)
6558 transparent ethernet bridging
86DD IPv6
</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;6&nbsp;</b></font><br /></td></tr></table><hr class="insert" />



<a name="anchor18"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.6"></a><h3>4.6.&nbsp;
payload</h3>

<p>A packet of the type payload type (e.g. an IP packet).
</p>
<a name="anchor19"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.7"></a><h3>4.7.&nbsp;
padding (OPTIONAL)</h3>

<p>Padding of max 255 octets.
None of the pre-defined encryption transforms uses any padding; for
   these, the plaintext and encrypted payload sizes match exactly. Transforms are based on transforms of the SRTP protocol and these transforms might use the RTP padding format, so a RTP like padding is supported. If the padding count field is present, than the padding count field MUST be set to the padding length.
</p>
<a name="anchor20"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.8"></a><h3>4.8.&nbsp;
padding count (OPTIONAL)</h3>

<p>The number of octets of the padding field. This field is optional. It's presence is signaled by the key management and not by this protocol. If this field isn't present, the padding field MUST NOT be present as well.
</p>
<a name="anchor21"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.9"></a><h3>4.9.&nbsp;
MKI (OPTIONAL)</h3>

<p>The MKI (Master Key Identifier) is OPTIONAL and of configurable length. See <a class='info' href='#RFC3711'>SRTP Section 3.1<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1] for details
</p>
<a name="anchor22"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.10"></a><h3>4.10.&nbsp;
authentication tag (RECOMMENDED)</h3>

<p>The authentication tag is RECOMMENDED and of configurable length. It contains a cryptographic checksum of the sender ID, sequence number and the encrypted portion, but not of the MKI. On sender side encryption HAS TO be done before calculating the authentication tag. A receiver HAS TO calculate the authentication tag before decrypting the encrypted portion.
</p>
<a name="anchor23"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.4.11"></a><h3>4.11.&nbsp;
Encryption</h3>

<p>Encryption is done in the same way as for <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1]. This section will only discuss some small changes that HAVE TO be made. Please read  <a class='info' href='#RFC3711'>SRTP RFC3711 section 3-9<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1] for details. 
</p>
<p>The least significant bits of SSRC are replaced by the sender ID and the most significant bits are replaced by the mux. For the SRTP SEQ the 16 least significant bits of the SATP sequence number are used and the 16 most significant bits of the sequence number replace the 16 least significant bits of the SRTP ROC.
</p><br /><hr class="insert" />
<a name="srtp_vs_satp"></a>

<p>Difference between SRTP and SATP
</p><div style='display: table; width: 0; margin-left: 3em; margin-right: auto'><pre>
      0                   1                   2                   3
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                     SATP    sequence number                   |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                     =
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |  SRTP ROC least significant   |           SRTP SEQ            |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


      0                   1                   2                   3
      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
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |           SATP  MUX           |       SATP sender ID          |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
                                     =
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     |                           SRTP SSRC                           |
     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
</pre></div><table border="0" cellpadding="0" cellspacing="2" align="center"><tr><td align="center"><font face="monaco, MS Sans Serif" size="1"><b>&nbsp;Figure&nbsp;7&nbsp;</b></font><br /></td></tr></table><hr class="insert" />

<a name="anchor24"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.5"></a><h3>5.&nbsp;
Security Considerations</h3>

<p>As SATP uses the same encryption techniques as <a class='info' href='#RFC3711'>SRTP<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1], it shares the same security issues. This section will only discuss some small changes. Please read  <a class='info' href='#RFC3711'>SRTP RFC3711 section 9<span> (</span><span class='info'>Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;The Secure Real-time Transport Protocol (SRTP),&rdquo; March&nbsp;2004.</span><span>)</span></a> [1] for details.
</p>
<a name="anchor25"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.5.1"></a><h3>5.1.&nbsp;
Replay protection</h3>

<p>Replay protection is done by a replay list. Every anycast receiver has it's own replay list, which SHOULDN'T be syncronised, because of massive overhead. This leads to an additional possible attack. A attacker is able to replay a captured packet once to every anycast receiver. This attack is considered of be very unlikely, because multiple attack hosts in different loactions are needed to reach the seperate anycast receivers and the number of replays is limited to the count of receivers - 1. Such replays might also happen because of routing problems, so a payload protocol HAS TO be robust against a small number of duplicated packages. The window size and position HAS TO be syncronised between multible anycast receivers to limit this attack.
</p>
<a name="anchor26"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.6"></a><h3>6.&nbsp;
IANA Considerations</h3>

<p>The protocol is intended to be used on top of IP or on top of UDP (to be compatible with NAT routers), so UDP and IP protocol numbers have to be assiged by IANA.
</p>
<a name="rfc.references"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<a name="rfc.section.7"></a><h3>7.&nbsp;
References</h3>

<a name="rfc.references1"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<h3>7.1.&nbsp;Normative References</h3>
<table width="99%" border="0">
<tr><td class="author-text" valign="top"><a name="RFC3711">[1]</a></td>
<td class="author-text">Baugher, M., McGrew, D., Naslund, M., Carrara, E., and K. Norrman, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc3711.txt">The Secure Real-time Transport Protocol (SRTP)</a>,&rdquo; RFC&nbsp;3711, March&nbsp;2004.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2119">[2]</a></td>
<td class="author-text"><a href="mailto:sob@harvard.edu">Bradner, S.</a>, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">Key words for use in RFCs to Indicate Requirement Levels</a>,&rdquo; BCP&nbsp;14, RFC&nbsp;2119, March&nbsp;1997 (<a href="ftp://ftp.isi.edu/in-notes/rfc2119.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2119.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2119.xml">XML</a>).</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2003">[3]</a></td>
<td class="author-text"><a href="mailto:perk@watson.ibm.com">Perkins, C.</a>, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc2003.txt">IP Encapsulation within IP</a>,&rdquo; RFC&nbsp;2003, October&nbsp;1996 (<a href="ftp://ftp.isi.edu/in-notes/rfc2003.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2003.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2003.xml">XML</a>).</td></tr>
</table>

<a name="rfc.references2"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<h3>7.2.&nbsp;Informational References</h3>
<table width="99%" border="0">
<tr><td class="author-text" valign="top"><a name="RFC2784">[4]</a></td>
<td class="author-text"><a href="mailto:dino@procket.com">Farinacci, D.</a>, <a href="mailto:tony1@home.net">Li, T.</a>, <a href="mailto:stan_hanks@enron.net">Hanks, S.</a>, <a href="mailto:dmm@cisco.com">Meyer, D.</a>, and <a href="mailto:pst@juniper.net">P. Traina</a>, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc2784.txt">Generic Routing Encapsulation (GRE)</a>,&rdquo; RFC&nbsp;2784, March&nbsp;2000.</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC2401">[5]</a></td>
<td class="author-text"><a href="mailto:kent@bbn.com">Kent, S.</a> and <a href="mailto:rja@corp.home.net">R. Atkinson</a>, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc2401.txt">Security Architecture for the Internet Protocol</a>,&rdquo; RFC&nbsp;2401, November&nbsp;1998 (<a href="ftp://ftp.isi.edu/in-notes/rfc2401.txt">TXT</a>, <a href="http://xml.resource.org/public/rfc/html/rfc2401.html">HTML</a>, <a href="http://xml.resource.org/public/rfc/xml/rfc2401.xml">XML</a>).</td></tr>
<tr><td class="author-text" valign="top"><a name="RFC1546">[6]</a></td>
<td class="author-text"><a href="mailto:craig@bbn.com">Partridge, C.</a>, <a href="mailto:tmendez@bbn.com">Mendez, T.</a>, and <a href="mailto:milliken@bbn.com">W. Milliken</a>, &ldquo;<a href="ftp://ftp.isi.edu/in-notes/rfc1546.txt">Host Anycasting Service</a>,&rdquo; RFC&nbsp;1546, November&nbsp;1993.</td></tr>
</table>

<a name="rfc.authors"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<h3>Author's Address</h3>
<table width="99%" border="0" cellpadding="0" cellspacing="0">
<tr><td class="author-text">&nbsp;</td>
<td class="author-text">Othmar Gsenger</td></tr>
<tr><td class="author-text">&nbsp;</td>
<td class="author-text">Puerstingerstr 32</td></tr>
<tr><td class="author-text">&nbsp;</td>
<td class="author-text">Saalfelden  5760</td></tr>
<tr><td class="author-text">&nbsp;</td>
<td class="author-text">AT</td></tr>
<tr><td class="author" align="right">Phone:&nbsp;</td>
<td class="author-text"></td></tr>
<tr><td class="author" align="right">Email:&nbsp;</td>
<td class="author-text"><a href="mailto:satp@gsenger.com">satp@gsenger.com</a></td></tr>
<tr><td class="author" align="right">URI:&nbsp;</td>
<td class="author-text"><a href="http://www.gsenger.com/satp/">http://www.gsenger.com/satp/</a></td></tr>
</table>
<a name="rfc.copyright"></a><br /><hr />
<table summary="layout" cellpadding="0" cellspacing="2" class="TOCbug" align="right"><tr><td class="TOCbug"><a href="#toc">&nbsp;TOC&nbsp;</a></td></tr></table>
<h3>Full Copyright Statement</h3>
<p class='copyright'>
Copyright &copy; The Internet Society (2008).</p>
<p class='copyright'>
This document is subject to the rights,
licenses and restrictions contained in BCP&nbsp;78,
and except as set forth therein,
the authors retain all their rights.</p>
<p class='copyright'>
This document and the information contained herein are provided
on an &ldquo;AS IS&rdquo; basis and THE CONTRIBUTOR,
THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY),
THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM
ALL WARRANTIES,
EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.</p>
<h3>Intellectual Property</h3>
<p class='copyright'>
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&nbsp;78 and BCP&nbsp;79.</p>
<p class='copyright'>
Copies of IPR disclosures made to the IETF Secretariat and any
assurances of licenses to be made available,
or the result of an attempt made to obtain a general license or
permission for the use of such proprietary rights by implementers or
users of this specification can be obtained from the IETF on-line IPR
repository at <a href='http://www.ietf.org/ipr'>http://www.ietf.org/ipr</a>.</p>
<p class='copyright'>
The IETF invites any interested party to bring to its attention
any copyrights,
patents or patent applications,
or other
proprietary rights that may cover technology that may be required
to implement this standard.
Please address the information to the IETF at <a href='mailto:ietf-ipr@ietf.org'>ietf-ipr@ietf.org</a>.</p>
<h3>Acknowledgment</h3>
<p class='copyright'>
Funding for the RFC Editor function is provided by
the IETF Administrative Support Activity (IASA).</p>
</body></html>