Problem in making call via asterisk?

I have registered two IP phones to my Asterisk Server13.8-cert4:

  1. Zoiper (Softphone)
  2. Grandstream (Hardphone)
    both are successfully registered to asterisk server, checked by ’sip show peers’, gives:

…comedia status …
No unmonitored
No unmonitored

i am facing two issues here:

  1. making call from Grandstream to Zoiper failes with output:
    chan_sip.c:process_sdp: rejecting secure audio stream without encryption details…
    how to enable sdp protocol?

  2. making call from Zoiper to Grandstream does not initiate communication i.e on picking credal call hangsup with:
    everyone is busy at this time
    —Auto Fallthrough, Channel ‘SIP/Zoiper-00000088’ status is ‘CHANUNAVAIL’

i think both issues are linked. how to fix them?
i am using very basic PBX server with sip.conf:
[Zoiper]
type=friend
username=Zoiper
secret=z123
host=dynamic
context=user

[Gstream]
type=friend
username=Gstream
secret=g123
host=dynamic
context=user

and Dialplan:
exten => 3010,1,Dial(SIP/Zoiper,20)
exten => 3011,1,Dial(SIP/Gstream,20)

The first needs to be fixed on the phone, unless it is a secondary error, because you are not configured for encryption. Disable encryption on the phone.

The second one is a secondary error. Please provide the primary failure and, preferably, the dip set debug on output for the INVITE transaction.

The debug output would also be needed for the first problem, if you actually wanted media encryption.

there is no encryption set for both phones as well as in asterisk configuration checked by “sip show peer Gstream/Zoiper”. on replacing hardphone with another one…problem get solved…seems Gstream had some configuration issues…or something i could not figure out…