[ndnSIM] length of interest packet

[Junxiao Shi]

Hi

Upon more careful inspection, the second packet is a Nack, not an Interest.
"fd032005fd03210196" in front of the Interest is the Nack header, as
defined https://redmine.named-data.net/projects/nfd/wiki/NDNLPv2 .
Sorry for not spotting it at the first look, because I can hardly remember
the hexadecimal numbers for NDNLPv2.

I'd recommend NDN Packet Dissector for Wireshark
<https://github.com/named-data/ndn-tools/tree/master/tools/dissect-wireshark>
so
you can inspect packets more easily without having to read hex numbers
directly.

Yours, Junxiao

On Thu, Dec 21, 2017 at 11:48 AM, 5 project <project5.is.tus at gmail.com>
wrote:

> Hi.
>
> Thanks for the advice.
>
> Do you know why it differs by 9?
>
> Thanks!
>
> 2017-12-19 21:58 GMT+09:00 Junxiao Shi <shijunxiao at email.arizona.edu>:
>
>> Hi
>>
>> The length for both Interests are 29 octets. Anything before “051b” or
>> after “0a04f2b1c1d0” belong to lower layers.
>> Interests are of non-zero length because they need to carry the name and
>> other fields. It’s the same reason why HTTP requests are of non-zero length.
>>
>> Yours, Junxiao
>>
>> On Mon, Dec 18, 2017 at 23:13 5 project <project5.is.tus at gmail.com>
>> wrote:
>>
>>> Hi!
>>>
>>> I am checking the packet in the pcap file.
>>> Why is there some lengths in interest packets?
>>> For example,
>>> 1. time: 9e-05 Length:75 Source:01
>>> 08800000ffffffffffff000000000001000000000
>>> 0010000aaaa030000007777642554010055010050
>>> 1d051b070f08067072656669780801350802fe000
>>> a04f2b1c10d0c0207d000000000
>>>
>>> 3. time: 0.003853 Length:84 Source:12
>>> 08800000ffffffffffff000000000012000000000
>>> 0121000aaaa030000007777642e540100550111fd
>>> 032005fd03210196501d051b070f0806707265666
>>> 9780801350802fe000a04f2b1c10d0c0207d00000
>>> 0000
>>>
>>> I'm experimenting in a wireless environment.
>>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.lists.cs.ucla.edu/pipermail/ndnsim/attachments/20171221/efd04777/attachment.html>