Re: [dtn-users] LTP Convergence Layer - Help needed!

["Zoller, David A. (MSFC-EO50)[HOSC SERVICES CONTRACT]" <[e-mail]>]

Hi Nik,
It has been a good while since I worked with the LTPLib and I never tried a setup like your node2, but, your configs look reasonable to me.
I suggest getting the second 2 node setup from “2 to 3” (assuming you did the “1 to 2” connection) working standalone and then combine the #2 configs.
--
You can try removing the local port from the links – I think by default the LTPLib uses a dynamic port for each session and specifying it might interfere.

You also might try setting the option   ion_mode=true  on both the interface and link add statements to see if that changes the behavior. That kind of negates the dynamic port usage.
Best regards,
DZ

From: Nik Ansell [mailto:[e-mail]]
Sent: Thursday, December 03, 2015 12:08 PM
To: Zoller, David A. (MSFC-EO50)[HOSC SERVICES CONTRACT]
Cc: [e-mail]
Subject: Re: [dtn-users] LTP Convergence Layer - Help needed!

Hi David,

Thank you for your kind reply, you are 100% correct.
The very helpful "Interface list" command told me that it was indeed listening on port 1113.  So I updated my config files to use port 1113 but it still didn't work.

I did however manage to get a 2 node setup working using port 1113, as per my previous update.

Do you know of any else I can do to troubleshoot the 3node setup?


Kind Regards,
Nik

On Thu, Dec 3, 2015 at 10:04 PM, Zoller, David A. (MSFC-EO50)[HOSC SERVICES CONTRACT] <[e-mail]<mailto:[e-mail]>> wrote:
Hi Nik,
interface add ltp0 ltp local_addr=$shorthostname is probably listening on port 1113 by default and your LTP links are transmitting to port 4556.
I recommend changing the LTP links to use the IANA assigned port 1113. (The UDP interface is listening on 4556 by default).
Hope that gets you going,
DZ


From: dtn-users [mailto:[e-mail]<mailto:[e-mail]>] On Behalf Of Nik Ansell
Sent: Thursday, December 03, 2015 11:23 AM
To: [e-mail]<mailto:[e-mail]>
Subject: [dtn-users] LTP Convergence Layer - Help needed!

Hi,

I have successfully setup a 3 node UDPCL and TCPCL topology and am able to send bundles OK.

Next I installed LTPLib and rebuilt DTN2, ensuring that ./configure found the location of LTPlib OK.

I have updates the config files to use ltp, but for some reason no bundles seem to be sent or queued!

If anyone could shed any light on a possible problem I will be forever in their debt, as bundles just seem to disappear!

My testing so far has been starting dtnd on all 3 nodes, then running the dtnsend command twice to send 2 test bundles from node 1 to node 3.
"dtnsend -s dtn://tx.dtn/a -d dtn://rx.dtn/g -t m -p "hello""

I run dtnrecv on node 3:
"dtnrecv dtn://rx.dtn/g -q -o F#####.bin"

"bundle list" on nodes 1,2&3" returns zero bundles, so none are in the queue.
"bundle stats" on node 1 returns:
Bundle Statistics: 0 pending -- 0 custody -- -- bpq --  bpq -- 2 received -- 0 delivered -- 0 generated -- 2 transmitted -- 0 expired -- 0 duplicate -- 2 deleted -- 0 injected
"link dump link_ltp1" on node 1 returns:
Current link:
Link link_ltp1:
clayer: ltp
type: ALWAYSON
state: OPEN
deleted: false
nexthop: mx:4556
remote eid: dtn:none
mtu: 1400
min_retry_interval: 5
max_retry_interval: 600
idle_close_time: 0
potential_downtime: 30
prevhop_hdr: false
reincarnated: true
used in fwdlog: true
            local_addr: 255.255.255.255 local_port: 4556
            remote_addr: 10.0.0.2 remote_port: 4556
            mtu: 1400
            Red/Green balance: all red
            ION mode: false

Config files:

Node1
interface add udp0 udp
interface add ltp0 ltp local_addr=$shorthostname

#          Create link to MX
link add link_ltp1 mx:4556 ALWAYSON ltp mtu=1400 local_port=4556 remote_port=4556 remote_addr=10.0.0.2

#          Add route to RX via MX
route add dtn://rx.dtn/* link_ltp1

Node2:
interface add udp0 udp
interface add ltp0 ltp local_addr=$shorthostname

#          Create link to TX
link add link_ltp2 tx:4556 ALWAYSON ltp local_port=4556 remote_port=4556 mtu=1400 remote_addr=10.0.0.1

#          Create link to RX
link add link_ltp3 rx:4556 ALWAYSON ltp local_port=4556 remote_port=4556 mtu=140 remote_addr=10.0.0.3

#          Add route to TX
route add dtn://tx.dtn/* link_ltp2

#          Add route to RX
route add dtn://rx.dtn/* link_ltp3

Node3:
interface add udp0 udp
interface add ltp0 ltp local_addr=$shorthostname

#          Create link to MK
link add link_ltp1 mx:4556 ALWAYSON ltp local_port=4556 remote_port=4556 remote_addr=10.0.0.2

#          Add route to TX via MX
route add dtn://tx.dtn/* link_ltp1

Kind Regards,
Nik