summaryrefslogtreecommitdiff
path: root/2018/phone_protocol-eh2018/gprs_pdp_ctx_act.svg
blob: fff4e9039f81dfc5db2dd1056fe63aa2e2124080 (plain)
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
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
 "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1"
 width="1800px" height="644px"
 viewBox="0 0 1800 644"
 xmlns="http://www.w3.org/2000/svg" shape-rendering="crispEdges"
 stroke-width="1" text-rendering="geometricPrecision">
<polygon fill="white" points="139,7 159,7 159,16 139,16"/>
<text x="150" y="16" textLength="18" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

MS
</text>
<polygon fill="white" points="408,7 490,7 490,16 408,16"/>
<text x="450" y="16" textLength="80" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

BTS/BSC/PCU
</text>
<polygon fill="white" points="731,7 767,7 767,16 731,16"/>
<text x="750" y="16" textLength="34" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

SGSN
</text>
<polygon fill="white" points="1021,7 1077,7 1077,16 1021,16"/>
<text x="1050" y="16" textLength="55" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

GRX DNS
</text>
<polygon fill="white" points="1331,7 1367,7 1367,16 1331,16"/>
<text x="1350" y="16" textLength="35" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

GGSN
</text>
<polygon fill="white" points="1628,7 1670,7 1670,16 1628,16"/>
<text x="1650" y="16" textLength="41" font-family="Helvetica" font-size="12" fill="black" text-anchor="middle">

Internet
</text>
<line x1="150" y1="22" x2="150" y2="50" stroke="black"/>
<line x1="450" y1="22" x2="450" y2="50" stroke="black"/>
<line x1="750" y1="22" x2="750" y2="50" stroke="black"/>
<line x1="1050" y1="22" x2="1050" y2="50" stroke="black"/>
<line x1="1350" y1="22" x2="1350" y2="50" stroke="black"/>
<line x1="1650" y1="22" x2="1650" y2="50" stroke="black"/>
<line x1="150" y1="33" x2="450" y2="33" stroke="black"/>
<polygon fill="black" points="450,33 440,39 440,27"/>
<polygon fill="white" points="258,23 341,23 341,32 258,32"/>
<text x="259" y="32" textLength="81" font-family="Helvetica" font-size="12" fill="black">
L1 RACH burst
</text>
<line x1="150" y1="50" x2="150" y2="78" stroke="black"/>
<line x1="450" y1="50" x2="450" y2="78" stroke="black"/>
<line x1="750" y1="50" x2="750" y2="78" stroke="black"/>
<line x1="1050" y1="50" x2="1050" y2="78" stroke="black"/>
<line x1="1350" y1="50" x2="1350" y2="78" stroke="black"/>
<line x1="1650" y1="50" x2="1650" y2="78" stroke="black"/>
<line x1="150" y1="61" x2="450" y2="61" stroke="black"/>
<polygon fill="black" points="450,61 440,67 440,55"/>
<polygon fill="black" points="150,61 160,67 160,55"/>
<polygon fill="white" points="220,51 379,51 379,60 220,60"/>
<text x="221" y="60" textLength="157" font-family="Helvetica" font-size="12" fill="black">
RLC/MAC TBF establishment
</text>
<line x1="150" y1="78" x2="150" y2="106" stroke="black"/>
<line x1="450" y1="78" x2="450" y2="106" stroke="black"/>
<line x1="750" y1="78" x2="750" y2="106" stroke="black"/>
<line x1="1050" y1="78" x2="1050" y2="106" stroke="black"/>
<line x1="1350" y1="78" x2="1350" y2="106" stroke="black"/>
<line x1="1650" y1="78" x2="1650" y2="106" stroke="black"/>
<line x1="150" y1="89" x2="450" y2="89" stroke="black"/>
<polygon fill="black" points="450,89 440,95 440,83"/>
<polygon fill="white" points="167,79 431,79 431,88 167,88"/>
<text x="168" y="88" textLength="262" font-family="Helvetica" font-size="12" fill="black">
RLC/MAC (LLC (SM PDP CONTEXT ACT REQ))
</text>
<polygon fill="white" points="242,90 356,90 356,99 242,99"/>
<text x="243" y="99" textLength="112" font-family="Helvetica" font-size="12" fill="black">
APN=internet.foo.bar
</text>
<line x1="150" y1="106" x2="150" y2="134" stroke="black"/>
<line x1="450" y1="106" x2="450" y2="134" stroke="black"/>
<line x1="750" y1="106" x2="750" y2="134" stroke="black"/>
<line x1="1050" y1="106" x2="1050" y2="134" stroke="black"/>
<line x1="1350" y1="106" x2="1350" y2="134" stroke="black"/>
<line x1="1650" y1="106" x2="1650" y2="134" stroke="black"/>
<line x1="450" y1="117" x2="750" y2="117" stroke="black"/>
<polygon fill="black" points="750,117 740,123 740,111"/>
<polygon fill="white" points="454,107 745,107 745,116 454,116"/>
<text x="455" y="116" textLength="289" font-family="Helvetica" font-size="12" fill="black">
BSSGP UL-UD (LLC (SM PDP CONTEXT ACT REQ))
</text>
<polygon fill="white" points="542,118 656,118 656,127 542,127"/>
<text x="543" y="127" textLength="112" font-family="Helvetica" font-size="12" fill="black">
APN=internet.foo.bar
</text>
<line x1="150" y1="134" x2="150" y2="162" stroke="black"/>
<line x1="450" y1="134" x2="450" y2="162" stroke="black"/>
<line x1="750" y1="134" x2="750" y2="162" stroke="black"/>
<line x1="1050" y1="134" x2="1050" y2="162" stroke="black"/>
<line x1="1350" y1="134" x2="1350" y2="162" stroke="black"/>
<line x1="1650" y1="134" x2="1650" y2="162" stroke="black"/>
<line x1="750" y1="145" x2="1050" y2="145" stroke="black"/>
<polygon fill="black" points="1050,145 1040,151 1040,139"/>
<polygon fill="white" points="817,135 981,135 981,144 817,144"/>
<text x="818" y="144" textLength="162" font-family="Helvetica" font-size="12" fill="black">
DNS Lookup A record for APN
</text>
<polygon fill="white" points="795,146 1004,146 1004,155 795,155"/>
<text x="796" y="155" textLength="207" font-family="Helvetica" font-size="12" fill="black">
internet.foo.bar.mncXXX.mccYYY.gprs
</text>
<line x1="150" y1="162" x2="150" y2="190" stroke="black"/>
<line x1="450" y1="162" x2="450" y2="190" stroke="black"/>
<line x1="750" y1="162" x2="750" y2="190" stroke="black"/>
<line x1="1050" y1="162" x2="1050" y2="190" stroke="black"/>
<line x1="1350" y1="162" x2="1350" y2="190" stroke="black"/>
<line x1="1650" y1="162" x2="1650" y2="190" stroke="black"/>
<line x1="1050" y1="173" x2="750" y2="173" stroke="black"/>
<polygon fill="black" points="750,173 760,179 760,167"/>
<polygon fill="white" points="810,163 989,163 989,172 810,172"/>
<text x="811" y="172" textLength="177" font-family="Helvetica" font-size="12" fill="black">
DNS Response A record for APN
</text>
<polygon fill="white" points="795,174 1004,174 1004,183 795,183"/>
<text x="796" y="183" textLength="207" font-family="Helvetica" font-size="12" fill="black">
internet.foo.bar.mncXXX.mccYYY.gprs
</text>
<line x1="150" y1="190" x2="150" y2="218" stroke="black"/>
<line x1="450" y1="190" x2="450" y2="218" stroke="black"/>
<line x1="750" y1="190" x2="750" y2="218" stroke="black"/>
<line x1="1050" y1="190" x2="1050" y2="218" stroke="black"/>
<line x1="1350" y1="190" x2="1350" y2="218" stroke="black"/>
<line x1="1650" y1="190" x2="1650" y2="218" stroke="black"/>
<polygon fill="white" points="608,190 892,190 892,212 608,212"/>
<line x1="608" y1="190" x2="892" y2="190" stroke="black"/>
<line x1="608" y1="212" x2="892" y2="212" stroke="black"/>
<line x1="608" y1="190" x2="608" y2="212" stroke="black"/>
<line x1="892" y1="190" x2="892" y2="212" stroke="black"/>
<polygon fill="white" points="621,197 878,197 878,206 621,206"/>
<text x="622" y="206" textLength="255" font-family="Helvetica" font-size="12" fill="black">
SGSN now knows IP address of GGSN for APN
</text>
<line x1="150" y1="218" x2="150" y2="246" stroke="black"/>
<line x1="450" y1="218" x2="450" y2="246" stroke="black"/>
<line x1="750" y1="218" x2="750" y2="246" stroke="black"/>
<line x1="1050" y1="218" x2="1050" y2="246" stroke="black"/>
<line x1="1350" y1="218" x2="1350" y2="246" stroke="black"/>
<line x1="1650" y1="218" x2="1650" y2="246" stroke="black"/>
<line x1="750" y1="229" x2="1350" y2="229" stroke="black"/>
<polygon fill="black" points="1350,229 1340,235 1340,223"/>
<polygon fill="white" points="953,219 1146,219 1146,228 953,228"/>
<text x="954" y="228" textLength="191" font-family="Helvetica" font-size="12" fill="black">
GTP-C (PDP CONTEXT ACT REQ)
</text>
<line x1="150" y1="246" x2="150" y2="274" stroke="black"/>
<line x1="450" y1="246" x2="450" y2="274" stroke="black"/>
<line x1="750" y1="246" x2="750" y2="274" stroke="black"/>
<line x1="1050" y1="246" x2="1050" y2="274" stroke="black"/>
<line x1="1350" y1="246" x2="1350" y2="274" stroke="black"/>
<line x1="1650" y1="246" x2="1650" y2="274" stroke="black"/>
<polygon fill="white" points="1208,246 1492,246 1492,268 1208,268"/>
<line x1="1208" y1="246" x2="1492" y2="246" stroke="black"/>
<line x1="1208" y1="268" x2="1492" y2="268" stroke="black"/>
<line x1="1208" y1="246" x2="1208" y2="268" stroke="black"/>
<line x1="1492" y1="246" x2="1492" y2="268" stroke="black"/>
<polygon fill="white" points="1290,253 1408,253 1408,262 1290,262"/>
<text x="1291" y="262" textLength="116" font-family="Helvetica" font-size="12" fill="black">
Allocate IPv4 address
</text>
<line x1="150" y1="274" x2="150" y2="302" stroke="black"/>
<line x1="450" y1="274" x2="450" y2="302" stroke="black"/>
<line x1="750" y1="274" x2="750" y2="302" stroke="black"/>
<line x1="1050" y1="274" x2="1050" y2="302" stroke="black"/>
<line x1="1350" y1="274" x2="1350" y2="302" stroke="black"/>
<line x1="1650" y1="274" x2="1650" y2="302" stroke="black"/>
<line x1="1350" y1="285" x2="750" y2="285" stroke="black"/>
<polygon fill="black" points="750,285 760,291 760,279"/>
<polygon fill="white" points="950,275 1149,275 1149,284 950,284"/>
<text x="951" y="284" textLength="197" font-family="Helvetica" font-size="12" fill="black">
GTP-C (PDP CONTEXT ACT RESP)
</text>
<polygon fill="white" points="1009,286 1089,286 1089,295 1009,295"/>
<text x="1010" y="295" textLength="78" font-family="Helvetica" font-size="12" fill="black">
IP addr + DNS
</text>
<line x1="150" y1="302" x2="150" y2="330" stroke="black"/>
<line x1="450" y1="302" x2="450" y2="330" stroke="black"/>
<line x1="750" y1="302" x2="750" y2="330" stroke="black"/>
<line x1="1050" y1="302" x2="1050" y2="330" stroke="black"/>
<line x1="1350" y1="302" x2="1350" y2="330" stroke="black"/>
<line x1="1650" y1="302" x2="1650" y2="330" stroke="black"/>
<line x1="750" y1="313" x2="450" y2="313" stroke="black"/>
<polygon fill="black" points="450,313 460,319 460,307"/>
<polygon fill="white" points="454,303 744,303 744,312 454,312"/>
<text x="455" y="312" textLength="288" font-family="Helvetica" font-size="12" fill="black">
BSSGP UL-UD (LLC (SM PDP CONTEXT ACT ACK))
</text>
<line x1="150" y1="330" x2="150" y2="358" stroke="black"/>
<line x1="450" y1="330" x2="450" y2="358" stroke="black"/>
<line x1="750" y1="330" x2="750" y2="358" stroke="black"/>
<line x1="1050" y1="330" x2="1050" y2="358" stroke="black"/>
<line x1="1350" y1="330" x2="1350" y2="358" stroke="black"/>
<line x1="1650" y1="330" x2="1650" y2="358" stroke="black"/>
<line x1="450" y1="341" x2="150" y2="341" stroke="black"/>
<polygon fill="black" points="150,341 160,347 160,335"/>
<polygon fill="white" points="168,331 431,331 431,340 168,340"/>
<text x="169" y="340" textLength="261" font-family="Helvetica" font-size="12" fill="black">
RLC/MAC (LLC (SM PDP CONTEXT ACT ACK))
</text>
<line x1="150" y1="358" x2="150" y2="386" stroke="black"/>
<line x1="450" y1="358" x2="450" y2="386" stroke="black"/>
<line x1="750" y1="358" x2="750" y2="386" stroke="black"/>
<line x1="1050" y1="358" x2="1050" y2="386" stroke="black"/>
<line x1="1350" y1="358" x2="1350" y2="386" stroke="black"/>
<line x1="1650" y1="358" x2="1650" y2="386" stroke="black"/>
<polygon fill="white" points="8,358 292,358 292,380 8,380"/>
<line x1="8" y1="358" x2="292" y2="358" stroke="black"/>
<line x1="8" y1="380" x2="292" y2="380" stroke="black"/>
<line x1="8" y1="358" x2="8" y2="380" stroke="black"/>
<line x1="292" y1="358" x2="292" y2="380" stroke="black"/>
<polygon fill="white" points="49,365 249,365 249,374 49,374"/>
<text x="50" y="374" textLength="198" font-family="Helvetica" font-size="12" fill="black">
MS now has IP addr + DNS server IP
</text>
<line x1="150" y1="386" x2="150" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="450" y1="386" x2="450" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="750" y1="386" x2="750" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="1050" y1="386" x2="1050" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="1350" y1="386" x2="1350" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="1650" y1="386" x2="1650" y2="403" stroke="black" stroke-dasharray="2,2"/>
<line x1="150" y1="403" x2="150" y2="431" stroke="black"/>
<line x1="450" y1="403" x2="450" y2="431" stroke="black"/>
<line x1="750" y1="403" x2="750" y2="431" stroke="black"/>
<line x1="1050" y1="403" x2="1050" y2="431" stroke="black"/>
<line x1="1350" y1="403" x2="1350" y2="431" stroke="black"/>
<line x1="1650" y1="403" x2="1650" y2="431" stroke="black"/>
<line x1="150" y1="414" x2="450" y2="414" stroke="black"/>
<polygon fill="black" points="450,414 440,420 440,408"/>
<polygon fill="white" points="197,404 401,404 401,413 197,413"/>
<text x="198" y="413" textLength="202" font-family="Helvetica" font-size="12" fill="black">
RLC/MAC (LLC (SNDCP (IP packet)))
</text>
<line x1="150" y1="431" x2="150" y2="459" stroke="black"/>
<line x1="450" y1="431" x2="450" y2="459" stroke="black"/>
<line x1="750" y1="431" x2="750" y2="459" stroke="black"/>
<line x1="1050" y1="431" x2="1050" y2="459" stroke="black"/>
<line x1="1350" y1="431" x2="1350" y2="459" stroke="black"/>
<line x1="1650" y1="431" x2="1650" y2="459" stroke="black"/>
<line x1="450" y1="442" x2="750" y2="442" stroke="black"/>
<polygon fill="black" points="750,442 740,448 740,436"/>
<polygon fill="white" points="484,432 715,432 715,441 484,441"/>
<text x="485" y="441" textLength="229" font-family="Helvetica" font-size="12" fill="black">
BSSGP UL-UD (LLC (SNDCP (IP packet)))
</text>
<line x1="150" y1="459" x2="150" y2="487" stroke="black"/>
<line x1="450" y1="459" x2="450" y2="487" stroke="black"/>
<line x1="750" y1="459" x2="750" y2="487" stroke="black"/>
<line x1="1050" y1="459" x2="1050" y2="487" stroke="black"/>
<line x1="1350" y1="459" x2="1350" y2="487" stroke="black"/>
<line x1="1650" y1="459" x2="1650" y2="487" stroke="black"/>
<line x1="750" y1="470" x2="1350" y2="470" stroke="black"/>
<polygon fill="black" points="1350,470 1340,476 1340,464"/>
<polygon fill="white" points="999,460 1100,460 1100,469 999,469"/>
<text x="1000" y="469" textLength="99" font-family="Helvetica" font-size="12" fill="black">
GTP-U (IP packet)
</text>
<line x1="150" y1="487" x2="150" y2="515" stroke="black"/>
<line x1="450" y1="487" x2="450" y2="515" stroke="black"/>
<line x1="750" y1="487" x2="750" y2="515" stroke="black"/>
<line x1="1050" y1="487" x2="1050" y2="515" stroke="black"/>
<line x1="1350" y1="487" x2="1350" y2="515" stroke="black"/>
<line x1="1650" y1="487" x2="1650" y2="515" stroke="black"/>
<line x1="1350" y1="498" x2="1650" y2="498" stroke="black"/>
<polygon fill="black" points="1650,498 1640,504 1640,492"/>
<polygon fill="white" points="1409,488 1589,488 1589,497 1409,497"/>
<text x="1410" y="497" textLength="178" font-family="Helvetica" font-size="12" fill="black">
IP packet (e.g. ICMP ECHO REQ
</text>
<line x1="150" y1="515" x2="150" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="450" y1="515" x2="450" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="750" y1="515" x2="750" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="1050" y1="515" x2="1050" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="1350" y1="515" x2="1350" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="1650" y1="515" x2="1650" y2="532" stroke="black" stroke-dasharray="2,2"/>
<line x1="150" y1="532" x2="150" y2="560" stroke="black"/>
<line x1="450" y1="532" x2="450" y2="560" stroke="black"/>
<line x1="750" y1="532" x2="750" y2="560" stroke="black"/>
<line x1="1050" y1="532" x2="1050" y2="560" stroke="black"/>
<line x1="1350" y1="532" x2="1350" y2="560" stroke="black"/>
<line x1="1650" y1="532" x2="1650" y2="560" stroke="black"/>
<line x1="1650" y1="543" x2="1350" y2="543" stroke="black"/>
<polygon fill="black" points="1350,543 1360,549 1360,537"/>
<polygon fill="white" points="1406,533 1593,533 1593,542 1406,542"/>
<text x="1407" y="542" textLength="185" font-family="Helvetica" font-size="12" fill="black">
IP packet (e.g. ICMP ECHO RESP
</text>
<line x1="150" y1="560" x2="150" y2="588" stroke="black"/>
<line x1="450" y1="560" x2="450" y2="588" stroke="black"/>
<line x1="750" y1="560" x2="750" y2="588" stroke="black"/>
<line x1="1050" y1="560" x2="1050" y2="588" stroke="black"/>
<line x1="1350" y1="560" x2="1350" y2="588" stroke="black"/>
<line x1="1650" y1="560" x2="1650" y2="588" stroke="black"/>
<line x1="1350" y1="571" x2="750" y2="571" stroke="black"/>
<polygon fill="black" points="750,571 760,577 760,565"/>
<polygon fill="white" points="999,561 1100,561 1100,570 999,570"/>
<text x="1000" y="570" textLength="99" font-family="Helvetica" font-size="12" fill="black">
GTP-U (IP packet)
</text>
<line x1="150" y1="588" x2="150" y2="616" stroke="black"/>
<line x1="450" y1="588" x2="450" y2="616" stroke="black"/>
<line x1="750" y1="588" x2="750" y2="616" stroke="black"/>
<line x1="1050" y1="588" x2="1050" y2="616" stroke="black"/>
<line x1="1350" y1="588" x2="1350" y2="616" stroke="black"/>
<line x1="1650" y1="588" x2="1650" y2="616" stroke="black"/>
<line x1="750" y1="599" x2="450" y2="599" stroke="black"/>
<polygon fill="black" points="450,599 460,605 460,593"/>
<polygon fill="white" points="484,589 715,589 715,598 484,598"/>
<text x="485" y="598" textLength="229" font-family="Helvetica" font-size="12" fill="black">
BSSGP DL-UD (LLC (SNDCP (IP packet)))
</text>
<line x1="150" y1="616" x2="150" y2="644" stroke="black"/>
<line x1="450" y1="616" x2="450" y2="644" stroke="black"/>
<line x1="750" y1="616" x2="750" y2="644" stroke="black"/>
<line x1="1050" y1="616" x2="1050" y2="644" stroke="black"/>
<line x1="1350" y1="616" x2="1350" y2="644" stroke="black"/>
<line x1="1650" y1="616" x2="1650" y2="644" stroke="black"/>
<line x1="450" y1="627" x2="150" y2="627" stroke="black"/>
<polygon fill="black" points="150,627 160,633 160,621"/>
<polygon fill="white" points="197,617 401,617 401,626 197,626"/>
<text x="198" y="626" textLength="202" font-family="Helvetica" font-size="12" fill="black">
RLC/MAC (LLC (SNDCP (IP packet)))
</text>
<line x1="150" y1="638" x2="150" y2="644" stroke="black"/>
<line x1="450" y1="638" x2="450" y2="644" stroke="black"/>
<line x1="750" y1="638" x2="750" y2="644" stroke="black"/>
<line x1="1050" y1="638" x2="1050" y2="644" stroke="black"/>
<line x1="1350" y1="638" x2="1350" y2="644" stroke="black"/>
<line x1="1650" y1="638" x2="1650" y2="644" stroke="black"/>
</svg>
personal git repositories of Harald Welte. Your mileage may vary