[hipl-users] Re: long delay in mobility handling procedure
- From: Szabolcs Nováczki <novaczkisz@xxxxxxxxx>
- To: hipl-users@xxxxxxxxxxxxx
- Date: Fri, 6 Mar 2009 16:12:37 +0100
Hi!
See my comments inline!
Br,
Szabi
2009/3/6 Tobias Heer <heer@xxxxxxxxxxxxxxxxx>
> Hi!
> Some thoughts on the handover performance:
>
> Have you tested how long your system takes to be ready to send an IP packet
> after the handover.
>
Not yet but sounds like a good idea, but how can you measure this.
In the hipd trace i see :
error(hipd.c:532@hipd_main): select() error: Interrupted system call.
Does this mean that select() reported that the socket on which hipd wants to
write to is not ready jet?
Could you have a look at the trace?
> We were doing tests without HIP with a Nokia N810 and it took almost 1
> second before we were able to send a IP packet after associating with a new
> AP. We tried different things to speed things up (setting routes and MAC
> addresses manually, etc.) but we weren't able to get better results whereas
> other devices showed much better results.
>
> DHCP also tends to slow things down quite a lot, so setting the IP
> addresses manually usually speeds things up.
>
We use IPv6 stateless autoconfig - no DHCP
> A third source of delay are the crypto operations necessary to compile the
> first update packet. It may take a some 100ms to compute the signature in
> the first update packet if you are using a particularly slow device (<400
> MHz) and long RSA or DSA keys as HIs.
>
The 2.13GHz Pentium with 2G RAM laptop we use as mobile should be fast
enough, I guess.
>
>
> I hope this provides some insights into the problem.
>
> BR,
>
> Tobias
>
>
>
> Am 06.03.2009 um 14:03 schrieb Szabolcs Nováczki:
>
> Hi!
>>
>> Yes, I did not get your message on the list. Wonder why...
>>
>> Anyway. Here is the answer:
>>
>> See my answers inline!
>>
>> #################
>> Hi,
>>
>> I will try do give some assistance but I need a bit more information about
>> the problem.
>> a) Could you provide some numbers in ms or s? What means significant? I
>> was
>> not able to read your attachment and it probably lacks timing information
>> anyway.
>> Sorry i forgot to give this info :). The delay is about 2 secs. I attached
>> the file again but you have right: there is no timing.
>>
>> b) Could you also give some detail about the machines you are working with
>> (CPU speed) ...
>> Ill send this later cause i am not sure of the detailes.
>>
>> c) ... and the test setup you are using (directly connected vs. sited at
>> different sites).
>> All is IPv6. There are three different /64 networks. One for the cn and
>> two
>> for the mobile. The cn is attached on wire. The mobile is attched to one
>> of
>> the latter two sites through wireless acces points and uses IPv6
>> stateless
>> autoconfiguration when receiving router advertisements to configure its IP
>> address. We use a script which periodically changes (iwconfig new_ap) from
>> one ap to the other and back. The mobile reconfigures its ip address which
>> triggers the hip update mechanism.
>>
>> d) Do you move between different (wireless?) networks?
>> see answer for c.)
>>
>> e) Are you using the same IP address in these different networks?
>> We use different addresses:
>> 2001:0738:2001:2084:0213:ceff:fe7b:fd28
>> 2001:0738:2001:2088:0213:ceff:fe7b:fd28
>>
>> BR,
>>
>> Tobias
>>
>> ##############
>>
>> Br,
>> Szabi
>>
>> 2009/3/6 Tobias Heer <tobias.heer@xxxxxx>
>>
>> Just in case you missed the message on the list...
>>>
>>>
>>> Anfang der weitergeleiteten E-Mail:
>>>
>>> Von: Tobias Heer <heer@xxxxxxxxxxxxxxxxx>
>>>
>>>> Datum: 6. März 2009 09:59:05 MEZ
>>>> An: "hipl-users@xxxxxxxxxxxxx" <hipl-users@xxxxxxxxxxxxx>
>>>> Kopie: Goodzi <goodzi@xxxxxx>
>>>> Betreff: Re: [hipl-users] long delay in mobility handling procedure
>>>>
>>>> Hi,
>>>>
>>>> I will try do give some assistance but I need a bit more information
>>>> about
>>>> the problem.
>>>> a) Could you provide some numbers in ms or s? What means significant? I
>>>> was not able to read your attachment and it probably lacks timing
>>>> information anyway.
>>>>
>>>> b) Could you also give some detail about the machines you are working
>>>> with
>>>> (CPU speed) ...
>>>>
>>>> c) ... and the test setup you are using (directly connected vs. sited at
>>>> different sites).
>>>>
>>>> d) Do you move between different (wireless?) networks?
>>>>
>>>> e) Are you using the same IP address in these different networks?
>>>>
>>>> BR,
>>>>
>>>> Tobias
>>>>
>>>> Am 06.03.2009 um 09:11 schrieb Szabolcs Nováczki:
>>>>
>>>> Hi hipl users!
>>>>
>>>>>
>>>>> We are doing some tests with infraHIP recently. With basic mobility
>>>>> tests
>>>>> we run into the following behaviour:
>>>>>
>>>>> There is a significant delay in infraHIP (on the mobile side) before
>>>>> sending out the first update package.
>>>>>
>>>>> I attached a commented trace of the hipd output (hipd_trace_medium)
>>>>> where
>>>>> I highlighted the suspected part.
>>>>>
>>>>> My request is that if some of you has time to analyze this or someone
>>>>> knows the reason for this behaviour please share with us! What happenes
>>>>> there? Is this delay ok? We are also interested of mechanisms
>>>>> triggering
>>>>> the update procedure in hipd, and how this trigger is processed.
>>>>>
>>>>> Thx!
>>>>>
>>>>> Br,
>>>>> Szabolcs Novaczki
>>>>>
>>>>> Ps.: hipd is running on 2.6.27-11 generic kernel installed from ubuntu
>>>>> interpid package
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Dipl.-Inform. Tobias Heer, Ph.D. Student
>>>> Distributed Systems Group
>>>> RWTH Aachen University, Germany
>>>> tel: +49 241 80 207 76
>>>> web: http://ds.cs.rwth-aachen.de/members/heer
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>> <hipd_trace_medium.txt>
>>
>
>
>
>
> --
> Dipl.-Inform. Tobias Heer, Ph.D. Student
> Distributed Systems Group
> RWTH Aachen University, Germany
> tel: +49 241 80 207 76
> web: http://ds.cs.rwth-aachen.de/members/heer
>
>
>
>
>
>
>
>
>
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