1 Reply Latest reply: Aug 4, 2017 2:02 AM by Kshitij S RSS

OOB Transparency

Kshitij S

I need to understand the OOB transparency scenarios in terms of Wireshark packet analysis. I have read SH  deployment guide , KB's on OOB but still not grasping the concept completely as I am finding contradiction in the wireshark in a lab setup. This has increased my confusion.


Note that below Scenarios are isolated.


Scenario 1.) The case is that FT is ON and OOB Transparency mode is set to None and default OOB port is set to 708. When I see the splice setup packet in wireshark I never see the source port as 708 in the inner channel. Although, I see correct IP's ( SIP is Client IP, Source Port is Random port NOT 708, DIP is server IP and Dest. Port is actual destination port in header). Why I never see 708 port as source in Splice setup packet.In this setup I changed the OOB transparency to FULL and still source port is not seen as 708 in inner channel splice.  Note that this is a lab setup.



Scenario 2.) In Full transparency I am not seeing the splice setup packet. Just the S+, SA++ and SA+ , Syn/Syn/Ack and Ack.

Usually, as soon as inner channel is setup OOB splice setup connection forms but , It is missing in the capture in this case  and the connection never appears in the current connection list.   I believe this is not normal.

When we say that oob splice forms after the first optimized connection , which optimized connection we refer ?  Connection pooling will not work in FT mode so no pooling  of connections . So, why I never see splice connection in this case , I believe this is the first connection and also please note that the connection never appears in current connections. Note that this is actual issue in the network.











  • Re: OOB Transparency
    Kshitij S

    I got an answer for Scenario 2 now, Outer channel was failing as no syn/ack was seen on SFE WAN interface , however S+* was seen. Hence, OOB splice was resetting as inner channel will be formed after SFE outer channel in case of EAD. However, Scenario 1 is still unclear ?