Transport cause transport resource unavailable

Transport Networks
1

Hello experts.
Can I know the reason for the below error intial context setup failure: transport cause transport resource unavailable?
Ping check from eNodeB to s1-c s1-u All found ok.
Iprt checked all relevant iprt defined both MME as well SGW.

2

I found in my network problem with partial reset issued from MME side.
Reason is transport network overload (sctp packet droped on interface level).
But it can be also but only if not configured properly transport network admission control reject on eNB.

3

Any counters related to eNodeB to confirm or only trace can help?
Huawei system.

4

@Bega82, for this case, was termpointtomme showing enabled or disabled?

5

Sorry I have no experience with HUAWEI EUTRAN to be able to provide you with counters and parameters.
But I beleive it is general behaviour of transport network that can be a bit twiked by SCTP parameter tuning.

6

Actually i mistook it as E/// system.
Yes there are list of sctp parameters which can be tweaked.
Thanks.

7

Note that these parameters have to be aligned on MME side adn eNb side.
I found that SCTP RTO max is sometimes having low value.
Also number of retransmissions needs to be considered.
I found in severeal networks that due to to Corona crisis traffic has been grown and despite SCTP is marked with DSCP=46 packets are dropped on ingress part of routers.
Especially if you have MW in transmission chain that makes situation more problematic.

8

Default SCTP RTO values in E///.

Transport - SctpProfile
initRto = 200
maxRto = 400
minRto = 100

9

Nokia:
RTOmax=30000ms