June 2009 - Test - lists.nanog.org

Interview: Patrik Fältström on the role of government in IPv6 deployment
by Alex Band 22 Jun '09

22 Jun '09

We uploaded another interview: http://www.youtube.com/watch?v=zrE1TEan4Jo To make sure we cover as many areas of the industry as possible, we asked Patrik Fältström on the role of government in IPv6 deployment. Patrik is Senior Consulting Engineer with Cisco, but has served as an advisor to the Swedish government on IT policy since 2003. In the interview, he makes a note about the American government as well. I hope you enjoy it. If you have feedback on specific topics you would like to see covered in future interviews, please let us know. We appreciate your comments. Alex Band RIPE NCC

1 0

Re: verizon issue?
by James Kennedy (TT) 22 Jun '09

22 Jun '09

Using there metro ethernet service we saw our circuit not recover after scheduled maintenance. Verizon backed out the change and our service was restored. ----- Original Message ----- From: Michael Ulitskiy <mulitskiy(a)acedsl.com> To: nanog(a)nanog.org <nanog(a)nanog.org> Sent: Mon Jun 22 12:32:48 2009 Subject: Re: verizon issue? Can you be more specific about the problem saw? We're having problems with their oc3 right now, not being able to push over 110m since this morning and still going on. And sure can't get anything useful from verizon. Thanks, Michael On Monday 22 June 2009 10:20:11 am James Kennedy (TT) wrote: > Yes, > > They did some maintenance that I think went bad. > > -----Original Message----- > From: sip vsp [mailto:sip.vsp.5060@gmail.com] > Sent: Monday, June 22, 2009 9:14 AM > To: nanog(a)nanog.org > Subject: verizon issue? > > Did anyone have trouble with Verizon over the weekend? > > >

3 2

verizon issue?
by sip vsp 22 Jun '09

22 Jun '09

Did anyone have trouble with Verizon over the weekend?

3 2

ipv6 only DNS?
by Steve Pirk 22 Jun '09

22 Jun '09

Anyone have any experience with dns and ipv6? I did a lookup on a host and it came back with only an ipv6 record. Also shows up in ident as a valid name. I was curious how an ipv6 only device would be able to hit my server. Details and more info off list, tonight if possible. -- steve

5 4

Re: Network Providers (bandwidth-only and others)
by William Pitcock 20 Jun '09

20 Jun '09

1. C 2. 3 3. Hosting equipment by far. 4. 5:95, where 5 is the bandwidth equipment. William ------Original Message------ From: Zartash Uzmi To: nanog(a)nanog.org Subject: Network Providers (bandwidth-only and others) Sent: Jun 20, 2009 12:29 PM I am trying to categorize service providers into: (A) those who provide bandwidth only to end users or to other providers (perhaps Sprint, AT&T, Verizon and many regional and national ISPs fall in this category). (B) those who provide network-related services other than bandwidth (hosting, storage, computing). Everything such as Amazon SSS, EC2, Akamai, GoDaddy, etc. falls here. (C) those who provide a mix of bandwidth only and non-bandwidth only services (many local ISPs and perhaps AOL?) It would be great if you could provide input by answering the VERY brief questions below (either privately or on the list). I will share the compilation and maintain privacy if that is important to you. It would be great if I get responses from small as well as larger providers on the list (you know who you are :) ). 1. Which category do you fall in (A, B, or C)? 2. How many POPs/Datacenters do you own? 3. If you belong to C, then per unit of your revenue in each category, what in your opinion requires more electricity: the bandwidth-provisioning equipment (routers, switches, MuXes, etc.) or the hosting/storage equipment (servers, SAN, etc.)? 4. If you belong to C, can you make a rough guess of the ratio of electricity required by bandwidth provisioning equipment to hosting/storage equipment, per unit of revenue in each case? Thanks for your input. Regards, Zartash -- William Pitcock SystemInPlace - Simple Hosting Solutions 1-866-519-6149

1 0

OT: Wireless Network Strength Dependent On Wired Network?
by Neil 20 Jun '09

20 Jun '09

Okay, a small, offtopic question. (I figured you guys were a far more reliable source than my local ${electronics_store} salesperson...) Consider the following setup: internet pipe -> wired network -> (wireless router) wireless network -> computer1, computer2 Suppose the signal coming in on the pipe is good, but the signal deteriorates rapidly in wired network (old & bad wiring). Now, the two computers are connected via the wireless network only. computer1 has a great connection (it's in the same room as the wireless router), but computer2 is far away and drops the wireless connection frequently. Now, a former electrical engineer is claiming that if we improve the wired network so that the signal comes across better, then computer2 won't drop the wireless connection so frequently. (He says that the signal emitted by the wireless router will be improved by feeding it a better source signal.) I argue that there are two separate signals: the internet connection signal coming in on the pipe, and then the wireless network signal being emitted from the wireless router; and their strengths are independent. In other words, if we improve the wiring, the wireless signal will not get any stronger. So...basically, who's right? (Or are neither of us?) Any thoughts, comments, corrections?

5 4

Network Providers (bandwidth-only and others)
by Zartash Uzmi 20 Jun '09

20 Jun '09

I am trying to categorize service providers into: (A) those who provide bandwidth only to end users or to other providers (perhaps Sprint, AT&T, Verizon and many regional and national ISPs fall in this category). (B) those who provide network-related services other than bandwidth (hosting, storage, computing). Everything such as Amazon SSS, EC2, Akamai, GoDaddy, etc. falls here. (C) those who provide a mix of bandwidth only and non-bandwidth only services (many local ISPs and perhaps AOL?) It would be great if you could provide input by answering the VERY brief questions below (either privately or on the list). I will share the compilation and maintain privacy if that is important to you. It would be great if I get responses from small as well as larger providers on the list (you know who you are :) ). 1. Which category do you fall in (A, B, or C)? 2. How many POPs/Datacenters do you own? 3. If you belong to C, then per unit of your revenue in each category, what in your opinion requires more electricity: the bandwidth-provisioning equipment (routers, switches, MuXes, etc.) or the hosting/storage equipment (servers, SAN, etc.)? 4. If you belong to C, can you make a rough guess of the ratio of electricity required by bandwidth provisioning equipment to hosting/storage equipment, per unit of revenue in each case? Thanks for your input. Regards, Zartash

1 0

Weekly Routing Table Report
by Routing Analysis Role Account 19 Jun '09

19 Jun '09

This is an automated weekly mailing describing the state of the Internet Routing Table as seen from APNIC's router in Japan. Daily listings are sent to bgp-stats(a)lists.apnic.net For historical data, please see http://thyme.apnic.net. If you have any comments please contact Philip Smith <pfs(a)cisco.com>. Routing Table Report 04:00 +10GMT Sat 20 Jun, 2009 Report Website: http://thyme.apnic.net Detailed Analysis: http://thyme.apnic.net/current/ Analysis Summary ---------------- BGP routing table entries examined: 288799 Prefixes after maximum aggregation: 137405 Deaggregation factor: 2.10 Unique aggregates announced to Internet: 143140 Total ASes present in the Internet Routing Table: 31502 Prefixes per ASN: 9.17 Origin-only ASes present in the Internet Routing Table: 27382 Origin ASes announcing only one prefix: 13343 Transit ASes present in the Internet Routing Table: 4120 Transit-only ASes present in the Internet Routing Table: 91 Average AS path length visible in the Internet Routing Table: 3.6 Max AS path length visible: 24 Max AS path prepend of ASN (12026) 22 Prefixes from unregistered ASNs in the Routing Table: 451 Unregistered ASNs in the Routing Table: 131 Number of 32-bit ASNs allocated by the RIRs: 177 Prefixes from 32-bit ASNs in the Routing Table: 49 Special use prefixes present in the Routing Table: 0 Prefixes being announced from unallocated address space: 847 Number of addresses announced to Internet: 2052918096 Equivalent to 122 /8s, 93 /16s and 11 /24s Percentage of available address space announced: 55.4 Percentage of allocated address space announced: 64.1 Percentage of available address space allocated: 86.4 Percentage of address space in use by end-sites: 77.4 Total number of prefixes smaller than registry allocations: 142968 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 68732 Total APNIC prefixes after maximum aggregation: 24540 APNIC Deaggregation factor: 2.80 Prefixes being announced from the APNIC address blocks: 68133 Unique aggregates announced from the APNIC address blocks: 30927 APNIC Region origin ASes present in the Internet Routing Table: 3666 APNIC Prefixes per ASN: 18.59 APNIC Region origin ASes announcing only one prefix: 999 APNIC Region transit ASes present in the Internet Routing Table: 565 Average APNIC Region AS path length visible: 3.5 Max APNIC Region AS path length visible: 18 Number of APNIC addresses announced to Internet: 454152304 Equivalent to 27 /8s, 17 /16s and 208 /24s Percentage of available APNIC address space announced: 84.6 APNIC AS Blocks 4608-4864, 7467-7722, 9216-10239, 17408-18431 (pre-ERX allocations) 23552-24575, 37888-38911, 45056-46079 APNIC Address Blocks 58/8, 59/8, 60/8, 61/8, 110/8, 111/8, 112/8, 113/8, 114/8, 115/8, 116/8, 117/8, 118/8, 119/8, 120/8, 121/8, 122/8, 123/8, 124/8, 125/8, 126/8, 180/8, 183/8, 202/8, 203/8, 210/8, 211/8, 218/8, 219/8, 220/8, 221/8, 222/8, ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 123570 Total ARIN prefixes after maximum aggregation: 66000 ARIN Deaggregation factor: 1.87 Prefixes being announced from the ARIN address blocks: 124331 Unique aggregates announced from the ARIN address blocks: 51877 ARIN Region origin ASes present in the Internet Routing Table: 13046 ARIN Prefixes per ASN: 9.53 ARIN Region origin ASes announcing only one prefix: 5010 ARIN Region transit ASes present in the Internet Routing Table: 1278 Average ARIN Region AS path length visible: 3.3 Max ARIN Region AS path length visible: 24 Number of ARIN addresses announced to Internet: 1009647680 Equivalent to 60 /8s, 46 /16s and 0 /24s Percentage of available ARIN address space announced: 194.1 ARIN AS Blocks 1-1876, 1902-2042, 2044-2046, 2048-2106 (pre-ERX allocations) 2138-2584, 2615-2772, 2823-2829, 2880-3153 3354-4607, 4865-5119, 5632-6655, 6912-7466 7723-8191, 10240-12287, 13312-15359, 16384-17407 18432-20479, 21504-23551, 25600-26591, 26624-27647, 29696-30719, 31744-33791 35840-36863, 39936-40959, 46080-47103 53248-55295 ARIN Address Blocks 24/8, 63/8, 64/8, 65/8, 66/8, 67/8, 68/8, 69/8, 70/8, 71/8, 72/8, 73/8, 74/8, 75/8, 76/8, 96/8, 97/8, 98/8, 99/8, 108/8, 173/8, 174/8, 184/8, 199/8, 204/8, 205/8, 206/8, 207/8, 208/8, 209/8, 216/8, RIPE Region Analysis Summary ---------------------------- Prefixes being announced by RIPE Region ASes: 66020 Total RIPE prefixes after maximum aggregation: 39077 RIPE Deaggregation factor: 1.69 Prefixes being announced from the RIPE address blocks: 65133 Unique aggregates announced from the RIPE address blocks: 43776 RIPE Region origin ASes present in the Internet Routing Table: 13167 RIPE Prefixes per ASN: 4.95 RIPE Region origin ASes announcing only one prefix: 6882 RIPE Region transit ASes present in the Internet Routing Table: 1977 Average RIPE Region AS path length visible: 3.9 Max RIPE Region AS path length visible: 22 Number of RIPE addresses announced to Internet: 482928800 Equivalent to 28 /8s, 200 /16s and 232 /24s Percentage of available RIPE address space announced: 102.8 RIPE AS Blocks 1877-1901, 2043, 2047, 2107-2136, 2585-2614 (pre-ERX allocations) 2773-2822, 2830-2879, 3154-3353, 5377-5631 6656-6911, 8192-9215, 12288-13311, 15360-16383 20480-21503, 24576-25599, 28672-29695 30720-31743, 33792-35839, 38912-39935 40960-45055, 47104-52223 RIPE Address Blocks 62/8, 77/8, 78/8, 79/8, 80/8, 81/8, 82/8, 83/8, 84/8, 85/8, 86/8, 87/8, 88/8, 89/8, 90/8, 91/8, 92/8, 93/8, 94/8, 95/8, 109/8, 178/8, 193/8, 194/8, 195/8, 212/8, 213/8, 217/8, LACNIC Region Analysis Summary ------------------------------ Prefixes being announced by LACNIC Region ASes: 23996 Total LACNIC prefixes after maximum aggregation: 5996 LACNIC Deaggregation factor: 4.00 Prefixes being announced from the LACNIC address blocks: 23861 Unique aggregates announced from the LACNIC address blocks: 13403 LACNIC Region origin ASes present in the Internet Routing Table: 1120 LACNIC Prefixes per ASN: 21.30 LACNIC Region origin ASes announcing only one prefix: 359 LACNIC Region transit ASes present in the Internet Routing Table: 188 Average LACNIC Region AS path length visible: 4.1 Max LACNIC Region AS path length visible: 19 Number of LACNIC addresses announced to Internet: 71607680 Equivalent to 4 /8s, 68 /16s and 165 /24s Percentage of available LACNIC address space announced: 71.1 LACNIC AS Blocks 26592-26623, 27648-28671, 52224-53247 plus ERX transfers LACNIC Address Blocks 186/8, 187/8, 189/8, 190/8, 200/8, 201/8, AfriNIC Region Analysis Summary ------------------------------- Prefixes being announced by AfriNIC Region ASes: 6085 Total AfriNIC prefixes after maximum aggregation: 1481 AfriNIC Deaggregation factor: 4.11 Prefixes being announced from the AfriNIC address blocks: 6480 Unique aggregates announced from the AfriNIC address blocks: 2496 AfriNIC Region origin ASes present in the Internet Routing Table: 301 AfriNIC Prefixes per ASN: 21.53 AfriNIC Region origin ASes announcing only one prefix: 93 AfriNIC Region transit ASes present in the Internet Routing Table: 62 Average AfriNIC Region AS path length visible: 3.8 Max AfriNIC Region AS path length visible: 15 Number of AfriNIC addresses announced to Internet: 20152832 Equivalent to 1 /8s, 51 /16s and 130 /24s Percentage of available AfriNIC address space announced: 60.1 AfriNIC AS Blocks 36864-37887 & ERX transfers AfriNIC Address Blocks 41/8, 197/8, APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /20 equiv MaxAgg Description 4766 1707 6931 402 Korea Telecom (KIX) 17488 1601 131 102 Hathway IP Over Cable Interne 4755 1214 327 138 TATA Communications formerly 9583 1106 87 546 Sify Limited 4134 890 16912 375 CHINANET-BACKBONE 7545 803 198 100 TPG Internet Pty Ltd 23577 782 34 665 Korea Telecom (ATM-MPLS) 18101 750 209 32 Reliance Infocom Ltd Internet 24560 718 230 175 Bharti Airtel Ltd. 9829 714 603 18 BSNL National Internet Backbo Complete listing at http://thyme.apnic.net/current/data-ASnet-APNIC ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 6389 4285 3647 324 bellsouth.net, inc. 4323 1866 1035 376 Time Warner Telecom 1785 1694 715 137 PaeTec Communications, Inc. 20115 1650 1449 723 Charter Communications 7018 1502 5926 1042 AT&T WorldNet Services 6478 1376 305 450 AT&T Worldnet Services 2386 1265 686 919 AT&T Data Communications Serv 3356 1206 10980 451 Level 3 Communications, LLC 11492 1116 208 12 Cable One 22773 1064 2604 66 Cox Communications, Inc. Complete listing at http://thyme.apnic.net/current/data-ASnet-ARIN RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 3292 455 1902 392 TDC Tele Danmark 12479 449 578 6 Uni2 Autonomous System 702 429 1861 346 UUNET - Commercial IP service 30890 416 88 196 Evolva Telecom 35805 353 40 5 United Telecom of Georgia 8866 352 109 21 Bulgarian Telecommunication C 3301 345 1668 308 TeliaNet Sweden 3215 342 3041 107 France Telecom Transpac 3320 339 7066 297 Deutsche Telekom AG 29049 317 26 3 AzerSat LLC. Complete listing at http://thyme.apnic.net/current/data-ASnet-RIPE LACNIC Region per AS prefix count summary ----------------------------------------- ASN No of nets /20 equiv MaxAgg Description 8151 1464 2863 236 UniNet S.A. de C.V. 10620 916 208 115 TVCABLE BOGOTA 22047 599 302 14 VTR PUNTO NET S.A. 7303 564 298 87 Telecom Argentina Stet-France 28573 549 563 38 NET Servicos de Comunicao S.A 11830 486 292 54 Instituto Costarricense de El 6471 443 96 32 ENTEL CHILE S.A. 11172 442 102 70 Servicios Alestra S.A de C.V 7738 404 794 28 Telecomunicacoes da Bahia S.A 3816 366 188 83 Empresa Nacional de Telecomun Complete listing at http://thyme.apnic.net/current/data-ASnet-LACNIC AfriNIC Region per AS prefix count summary ------------------------------------------ ASN No of nets /20 equiv MaxAgg Description 8452 987 188 7 TEDATA 24863 888 83 41 LINKdotNET AS number 20858 324 34 5 EgyNet 3741 277 856 237 The Internet Solution 2018 243 215 143 Tertiary Education Network 6713 175 166 16 Itissalat Al-MAGHRIB 33783 152 10 8 EEPAD TISP TELECOM & INTERNET 29571 139 15 8 Ci Telecom Autonomous system 5536 123 8 9 Internet Egypt Network 33776 116 6 7 Starcomms Nigeria Limited Complete listing at http://thyme.apnic.net/current/data-ASnet-AFRINIC Global Per AS prefix count summary ---------------------------------- ASN No of nets /20 equiv MaxAgg Description 6389 4285 3647 324 bellsouth.net, inc. 4323 1866 1035 376 Time Warner Telecom 4766 1707 6931 402 Korea Telecom (KIX) 1785 1694 715 137 PaeTec Communications, Inc. 20115 1650 1449 723 Charter Communications 17488 1601 131 102 Hathway IP Over Cable Interne 7018 1502 5926 1042 AT&T WorldNet Services 8151 1464 2863 236 UniNet S.A. de C.V. 6478 1376 305 450 AT&T Worldnet Services 2386 1265 686 919 AT&T Data Communications Serv Complete listing at http://thyme.apnic.net/current/data-ASnet Global Per AS Maximum Aggr summary ---------------------------------- ASN No of nets Net Savings Description 1785 1694 1557 PaeTec Communications, Inc. 17488 1601 1499 Hathway IP Over Cable Interne 4323 1866 1490 Time Warner Telecom 4766 1707 1305 Korea Telecom (KIX) 8151 1464 1228 UniNet S.A. de C.V. 11492 1116 1104 Cable One 4755 1214 1076 TATA Communications formerly 18566 1062 1052 Covad Communications 22773 1064 998 Cox Communications, Inc. 8452 987 980 TEDATA Complete listing at http://thyme.apnic.net/current/data-CIDRnet List of Unregistered Origin ASNs (Global) ----------------------------------------- Bad AS Designation Network Transit AS Description 16927 UNALLOCATED 12.0.252.0/23 7018 AT&T WorldNet Servic 15132 UNALLOCATED 12.9.150.0/24 7018 AT&T WorldNet Servic 32567 UNALLOCATED 12.14.170.0/24 7018 AT&T WorldNet Servic 13746 UNALLOCATED 12.24.56.0/24 7018 AT&T WorldNet Servic 32567 UNALLOCATED 12.25.107.0/24 7018 AT&T WorldNet Servic 26973 UNALLOCATED 12.39.152.0/24 7018 AT&T WorldNet Servic 26973 UNALLOCATED 12.39.154.0/23 7018 AT&T WorldNet Servic 26973 UNALLOCATED 12.39.159.0/24 7018 AT&T WorldNet Servic 32326 UNALLOCATED 12.40.49.0/24 7018 AT&T WorldNet Servic 25639 UNALLOCATED 12.41.169.0/24 7018 AT&T WorldNet Servic Complete listing at http://thyme.apnic.net/current/data-badAS Advertised Unallocated Addresses -------------------------------- Network Origin AS Description 41.223.112.0/22 5713 Telkom SA Ltd 41.223.176.0/22 36981 >>UNKNOWN<< 41.223.188.0/24 22351 Intelsat 41.223.189.0/24 26452 Local Communications Networks 62.61.220.0/24 24974 Tachyon Europe BV - Wireless 62.61.221.0/24 24974 Tachyon Europe BV - Wireless 63.140.213.0/24 22555 Universal Talkware Corporatio 63.143.251.0/24 22555 Universal Talkware Corporatio 64.31.32.0/19 11955 ServiceCo LLC - Road Runner 64.31.59.0/24 7017 ServiceCo LLC - Road Runner Complete listing at http://thyme.apnic.net/current/data-add-IANA Number of prefixes announced per prefix length (Global) ------------------------------------------------------- /1:0 /2:0 /3:0 /4:0 /5:0 /6:0 /7:0 /8:19 /9:10 /10:20 /11:59 /12:167 /13:348 /14:603 /15:1157 /16:10519 /17:4741 /18:8103 /19:16913 /20:20247 /21:20048 /22:25959 /23:25847 /24:151439 /25:870 /26:1019 /27:540 /28:149 /29:8 /30:6 /31:0 /32:8 Advertised prefixes smaller than registry allocations ----------------------------------------------------- ASN No of nets Total ann. Description 6389 2792 4285 bellsouth.net, inc. 4766 1400 1707 Korea Telecom (KIX) 17488 1313 1601 Hathway IP Over Cable Interne 1785 1171 1694 PaeTec Communications, Inc. 11492 1044 1116 Cable One 18566 1043 1062 Covad Communications 2386 978 1265 AT&T Data Communications Serv 9583 958 1106 Sify Limited 4323 954 1866 Time Warner Telecom 8452 920 987 TEDATA Complete listing at http://thyme.apnic.net/current/data-sXXas-nos Number of /24s announced per /8 block (Global) ---------------------------------------------- 4:13 8:205 12:2235 13:10 15:19 16:3 17:4 20:36 24:1083 32:52 34:2 38:572 40:97 41:1735 43:1 44:2 47:13 52:4 55:2 56:3 57:24 58:577 59:638 60:459 61:1078 62:1109 63:2017 64:3727 65:2381 66:3615 67:1632 68:829 69:2655 70:556 71:184 72:1672 73:2 74:1578 75:172 76:323 77:856 78:557 79:349 80:1003 81:833 82:561 83:434 84:632 85:1013 86:398 87:656 88:356 89:1446 90:57 91:2352 92:345 93:1077 94:1229 95:1064 96:141 97:219 98:248 99:23 109:1 110:150 111:18 112:134 113:123 114:249 115:336 116:1161 117:529 118:301 119:698 120:145 121:755 122:1034 123:701 124:992 125:1338 128:221 129:239 130:127 131:410 132:72 133:9 134:183 135:38 136:224 137:162 138:163 139:80 140:443 141:118 142:385 143:339 144:364 145:48 146:381 147:155 148:516 149:237 150:176 151:193 152:144 153:142 154:2 155:276 156:169 157:301 158:116 159:341 160:284 161:152 162:270 163:164 164:482 165:503 166:454 167:359 168:664 169:167 170:473 171:39 172:10 173:300 174:220 178:1 180:1 183:1 186:26 187:112 188:35 189:435 190:2796 192:5782 193:4242 194:3307 195:2698 196:1092 198:3606 199:3355 200:5089 201:1286 202:7913 203:8208 204:3848 205:2160 206:2437 207:2738 208:3888 209:3400 210:2673 211:1121 212:1558 213:1681 214:81 215:31 216:4530 217:1318 218:393 219:433 220:1226 221:485 222:305 End of report

1 0

OT: Someone is parroting Randy
by Frank Bulk 19 Jun '09

19 Jun '09

"'My competitors are welcome to them. They won't earn anything on them either." Says Marco Visser, head of KPN's mobile services division, in response to the press' inquiry whether their elimination of free phones for pay-as-you-go would result in an outflow of customers http://www.telegeography.com/cu/article.php?article_id=28943 <http://www.telegeography.com/cu/article.php?article_id=28943&email=html> &email=html

1 0

RE: Wireless bridge
by Patrick Shoemaker 19 Jun '09

19 Jun '09

Peter, to follow up on a few of your RF questions here: The idea behind the Fresnel zones is that objects (larger than one wavelength, a few centimeters at the frequencies we're dealing with here) within the zones will reflect the incoming radio wave from the transmitting radio. As seen by the receiver, there will be two signals- one coming directly from the transmitting antenna, and the reflection coming from the object in the Fresnel zone. The reflected signal, having a longer overall path length, will be slightly out of phase compared to the direct wave, and will destructively interfere with the direct wave, lowering the overall received power level seen by the receiving radio. This is called multipath interference. Therefore, unless you're using very high gain antennas (large parabolic dishes) with high directivity, you won't gain anything by pointing them at the sky or away from the object in the Fresnel zone. You'll lose more signal by mis-aiming the antennas than you will lose from the multipath interference. Regarding antenna polarization, your flat panel antennas are certainly polarized and must be oriented in the same polarization at each end. Finally, if you have a way to check the received power level at your existing radios, you will want to adjust the transmitter output power of each end so that the received power is within a reasonable range. Generally speaking, for a link of that distance, you should aim for something in the -60 dBm range. Anything hotter than a -50 and you start to get into front-end overload territory, and anything weaker than a -70 and you're beginning to run on thin fade margins. Also, I disagree that shielded Ethernet cable is unnecessary. For the very low additional cost of shielded outdoor cat-5, it's well worth your effort if you're running new cable. Of course every installation is different, but why risk ethernet errors due to some large air conditioner or something on the roof spewing EMI? Patrick Shoemaker Vector Data Systems LLC shoemakerp(a)vectordatasystems.com office: (301) 358-1690 x36 http://www.vectordatasystems.com > Message: 12 > Date: Thu, 18 Jun 2009 21:46:08 -0400 > From: "Peter Boone" <NANOG(a)Aquillar.com> > Subject: RE: Wireless bridge > To: <nanog(a)nanog.org> > Message-ID: <23ab01c9f07f$b7aa6480$26ff2d80$@com> > Content-Type: text/plain; charset="us-ascii" > > OK, from reading all the excellent feedback I've got on and off list I've > attempted to compile a "quick" summary of findings/ideas/products so far. > > - RouterBoard is no good for this type of application. > > - Get a unit with radio/antenna integrated, PoE from inside the building > (outdoor rated cat5, shielded I assume), lightning suppression for the PoE > (properly grounded), and ensure the mast is properly grounded. > > - Get off the 2.4 GHz range. Move up to 5. As for licensed vs. unlicensed, > I'm getting mixed input. I'm fairly certain that if the price is right and > the frequency is 5GHz+, it won't be a factor. Also, I'll be very glad to > separate the bridge from the client access points so that allows for more > options. Every solution at this range can easily do 20+ Mbps so throughput > is no longer a factor. > > - Products that support ARQ are highly recommended. > > - I'm hearing the same products mentioned over and over: > - Motorola > - Ubiquiti > - Aironet (Cisco) > - Aruba > A number of individuals recommended products from other brands at low cost > that meet these mentioned requirements too. > > > I'm not going to bother with a spectrum analyzer. In the current > implementation we tried channels 1, 6 and 11 for a few days at a time and > found 1 to be the most reliable. Done. At this point an analyzer will tell > me what I already suspect: there's a problem. > > I've researched the Fresnel zones and calculated out a few things with rough > numbers and worst case. For one, the Fresnel zone is disrupted most if the > obstruction is closer to the endpoints (e.g. antennas). In this case, this > is fine as the antenna are mounted at the outermost corner of the buildings > as close as possible to the other buildings, approximately 3 floors in the > air. Other buildings become a factor near the middle. Based on channel 1's > wavelength of 0.12438 m, and assuming 1 km apart (for simplicity sake. It's > actually less), the Fresnel zone is largest in the center at approx 5.6 m > radius. That could definitely be obstructed by rooftops, I'll have to take > another look though. This radius cuts in half when the frequency is doubled, > thus more evidence in favour of the 5 GHz+ range. Cool. Or we could just go > with a good line of sight optical solution but they look too expensive, and > this area can have very unforgiving fog/wind to disrupt things further. What > if we tilt each existing antenna up towards the sky 10-20 degrees? Please > correct me if I'm wrong. > > The current antennas are plates. I'm pretty sure they are polarized. I used > to have a product sheet on these but a Google search doesn't turn up any > useful results anymore (SmartAnt PCW24-03014-BFL). The way they are mounted > to the poles might make it difficult to try rotating them 90 degrees, but > worth another look. The coax between the AP and antennas are no longer than > 30 feet. I've often wondered if a Pringle or Coffee Cantenna would work > better than these! > > > For right now I'll have the coax line and ends inspected for > damage/softspots, check the grounding, and cover/re-cover the ends in large > amounts of rubber/electric tape. I think we might try the Ubiquiti Bullet2 > for approx $100 per side (PoE supply/lightning suppression, wiring included) > and see what happens! If that doesn't work, no major loss and we'll move up > to something more serious (the PoE and wiring will already be ready to go). > I will have to look into pricing on some of these suggestions and figure out > if we should even bother getting a Bullet but instead go straight to a > better all-in-one solution. > > Thank you guys very much for the tips. Feel free to keep them coming! > > Peter

1 0