RTT between India and HK PoP

[wahjava]

Hi all,

I did a traceroute to the HK PoP (216.218.221.6) from an Airtel (an Indian ISP). Following are my results:

Code Select Expand


% traceroute -I 216.218.221.6
traceroute to 216.218.221.6 (216.218.221.6), 64 hops max, 72 byte packets
1  * * *
2  ABTS-North-Static-246.220.160.122.airtelbroadband.in (122.160.220.246)  31.533 ms  42.310 ms  32.772 ms
3  rasBTNLDel-static-174.215.56.202.mantraonline.com (202.56.215.174)  33.040 ms  32.200 ms  35.445 ms
4  125.19.22.145 (125.19.22.145)  39.870 ms  31.754 ms  35.116 ms
5  59.145.6.62 (59.145.6.62)  84.515 ms  84.201 ms  84.951 ms
6  if-7-0-0.core1.S2E-Singapore.as6453.net (216.6.91.73)  113.055 ms  111.871 ms  109.877 ms
7  Vlan1124.icore1.S9U-Singapore.as6453.net (116.0.83.17)  126.084 ms  130.112 ms  126.356 ms
8  Vlan32.icore1.HK2-HongKong.as6453.net (116.0.83.2)  159.605 ms  150.740 ms  148.081 ms
9  hurricaneelectric-RGE.hkix.net (202.40.161.158)  321.999 ms  324.960 ms  324.916 ms
10  tserv20.hkg1.ipv6.he.net (216.218.221.6)  304.791 ms  304.445 ms  305.538 ms


Note the 150ms latency between 116.0.83.2 and 202.40.161.158, from their names it seems both of these boxes are located in HK. Then why is this latency of 150ms ?

I'm at present using London PoP (216.66.80.26) and a traceroute to that is given below:

Code Select Expand


% traceroute -I 216.66.80.26
traceroute to 216.66.80.26 (216.66.80.26), 64 hops max, 72 byte packets
1  * * *
2  ABTS-North-Static-246.220.160.122.airtelbroadband.in (122.160.220.246)  32.918 ms  33.959 ms  34.769 ms
3  ABTS-North-Static-158.230.160.122.airtelbroadband.in (122.160.230.158)  34.723 ms  32.785 ms  36.175 ms
4  125.19.22.145 (125.19.22.145)  34.925 ms  33.071 ms  30.976 ms
5  59.145.6.57 (59.145.6.57)  88.930 ms  90.327 ms  89.109 ms
6  so-2-3-0-zcr1.lnt.cw.net (166.63.222.53)  247.870 ms  250.581 ms  263.865 ms
7  so-3-0-0-bcr1.lnd.cw.net (166.63.163.221)  322.265 ms  248.611 ms  250.025 ms
8  xe-0-3-0.xcr1.lnd.cw.net (195.2.25.1)  249.050 ms
    xe-5-0-0-xcr1.lnd.cw.net (195.2.25.121)  245.164 ms  250.088 ms
9  xe-11-1-0.xcr1.lsw.cw.net (195.2.25.53)  254.536 ms
    xe-11-2-0.xcr1.lsw.cw.net (195.2.25.57)  248.405 ms
    xe-11-1-0.xcr1.lsw.cw.net (195.2.25.53)  251.785 ms
10  linx.he.net (195.66.224.21)  368.798 ms  371.511 ms  368.756 ms
11  tserv5.lon1.ipv6.he.net (216.66.80.26)  367.138 ms  365.565 ms  368.852 ms


Before the recent undersea cable cut, it used to be reachable in 250ms. I'm wondering if after the repair of undersea cable, HK PoP is going to be reachable any faster than London's PoP ?

Thanks
Ashish SHUKLA

[piojan]

Form the HE point of view (http://lg.he.net/cgi-bin/index.cgi)

Code Select Expand

Tracing the route to IP node ABTS-North-Static-246.220.160.122.airtelbroadband.in [122.160.220.246] from 1 to 30 hops

  1   179 ms  175 ms  175 ms v1026.core1.sjc1.he.net [72.52.92.173]
  2   173 ms  176 ms  176 ms 10gigabitethernet2-1.core1.sjc2.he.net [72.52.92.118]
  3   174 ms  174 ms  174 ms ge13-1.br02.sjo01.pccwbtn.net [206.223.116.48]
  4   454 ms  450 ms  451 ms bharti.pos11-0.cr02.sin02.pccwbtn.net [63.218.165.214]
  5   502 ms  503 ms  502 ms 203.101.100.186
  6   508 ms  508 ms  508 ms 125.19.22.146
  7   505 ms  503 ms  504 ms ABTS-North-Static-246.220.160.122.airtelbroadband.in [122.160.220.246]



Then why is this latency of 150ms ?

Becuose of different return routing paths.

So the peering with as6453.net is working in one way only. HE is returning the traffice to us via USA.
Probably it could be improve by HE.

PJ

EDIT:
also the frankfurt tserver is closest to u now: should be 255ms (216.66.80.30), hkg might be after a fix :P

[wahjava]

also the frankfurt tserver is closest to u now: should be 255ms (216.66.80.30), hkg might be after a fix :P

Thanks for the reply, but I didn't get why is there 150ms of latency between two routers placed in the same DC (or the same country) ? I agree with you about one way route between India and Hong Kong.

Any guesses which one will be faster if Hong Kong router gets 2-way peering and undersea cable gets fixed ? I guess then it will be Hong Kong, London, Frankfurt (in order of increasing RTTs).

[testmonster]

It's because your ISP (or their upstreams) does not advertise the return route to the HKIX exchange in Hong Kong.

By going to Hurricane Electric's looking glass at http://lg.he.net and selecting command "BGP", entering that IP where it says "Argument", selecting the Hong Kong router, we see the following output:

Number of BGP Routes matching display condition : 1
Status codes: s suppressed, d damped, h history, * valid, > best, i internal
Origin codes: i - IGP, e - EGP, ? - incomplete
    Network            Next Hop        Metric LocPrf Weight Path
*>i 122.160.220.0/24   206.223.116.48  1      100    0      3491 9498 24560 i
       Last update to IP routing table: 2h54m55s, 1 path(s) installed:

Hurricane sees this route from AS3491 (PCCW BTN).

A further traceroute from Hong Kong to the IP reveals that it goes back to the US, confirming that PCCW does not annouce this route at HKIX in Hong Kong.

[wahjava]

Okay. I didn't noticed this fact earlier.

Thanks everyone for the replies.