[nos-bbs] Remote AX25 Attach with JNOS

Andre v Schayk andre at pe1rdw.demon.nl
Thu Apr 7 02:52:13 EDT 2005


Barry Siegfried schreef:

>[maiko at pcs.mb.ca wrote]:
>
>  
>
>>>axip has the advantage that it has all the tcpip transport functions so
>>>you can be sure that everything that is send will get there in the end
>>>      
>>>
>>Sorry but that is not correct. See the following :
>>
>>  http://www.iana.org/assignments/protocol-numbers
>>    
>>
>
>Whew!  I'm glad Maiko cleared up that one!
>
>  
>
>>AXIP is an IP protocol, at the same level as the other IP protocols,
>>like UDP, TCP, ICMP, EGP, and the list goes on.
>>
>>AXIP is simply AX25 frames in IP.  There are no transport functions,
>>it's more or less raw IP.  There is no guarantee that the frames will
>>get to the other end.
>>    
>>
>
>Correct, BUT if you are encapsulating AX.25 VC frames, then the AX.25
>level 2 time out will see to it that any lost frames are resent.
>
>  
>
>>There has been talk in past times about having a AXTCP (which would see
>>AX25 Frames transported over TCPIP).  But I don't see the point of that.
>>    
>>
>
>*Particularly* since hams invented a level 2 "timeout" using VC mode
>it is not even necessary.  What about for UI frames you say?  Ah well,
>nothing is perfect.
>
>  
>
>>>where axudp has no garantees
>>>      
>>>
>>AXUDP is AX25 frames in UDP.  More or less the same functionaly as AXIP,
>>but with the extra size of the UDP header.  Functionally the same thing.
>>
>>    
>>
>>>axudp is easier to route over firewalls and routers.
>>>      
>>>
>>Yes.  AXIP is not easy or just impossible to route through alot of
>>the cheap home units.
>>
>>    
>>
>>>so if you can get it to work axip is better
>>>      
>>>
>>I would say for most DSL and Cable users, that AXUDP is a better choice,
>>since UDP is passed by most home and consumer routers, where anything
>>other than UDP, TCP, or ICMP (ie AXIP) likely will not make it.
>>    
>>
>
>If you need to use 44-net IP addresses for the end links of your
>AX.25 link and you have a cheap home cable router that won't pass
>anything other than ICMP, TCP and UDP, then you could use IPUDP
>(like IPIP only with the extra size of the UDP header) and then
>use your 44-net IP address to encapsulate an AXIP link to the
>other end.
>
>73, de Barry, K2MF >>
>  
>
I´m glad to see I´m still human and able to make mistakes :)
If there is a demand for the adopted ax25ipd that I made that will alow 
you to send everything you put into the ax25ipd to the other side of the 
axudp link just let me know (normaly ax25ipd will only send packets 
directed to the call you configured).

73 de Andre PE1RDW




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