linphone作为被叫无法使用SRTP呼通

最近测试freeswitch和linphone打电话。使用语音通道加密SRTP。发现以下问题：

1，linphone端使用SRTP可以去呼叫FREESWITCH，通讯正常。LOG里面能看到crypto的字段。

2，FREESWITCH也使用srtp去呼叫linphone，没声音，30S断。为什么？

在出向dialplan中已经加了下面内容

但是我使用microsip去测试又正常，为什么呢?

 

各种查资料，发现下面内容。

https://community.zoiper.com/5048/zoiper-srtp-crypto-mismatch-with-freeswitch

zoiper when using srtp sends the below crypto in SDP

a=crypto:5 AES_256_CM_HMAC_SHA1_80
a=crypto:6 AES_256_CM_HMAC_SHA1_32
a=crypto:3 AES_192_CM_HMAC_SHA1_80
a=crypto:4 AES_192_CM_HMAC_SHA1_32
a=crypto:1 AES_CM_128_HMAC_SHA1_80
a=crypto:2 AES_CM_128_HMAC_SHA1_32

 

whereas freeswitch prefers

AES_CM_256_HMAC_SHA1_80
AES_CM_192_HMAC_SHA1_80
AES_CM_128_HMAC_SHA1_80
AES_CM_256_HMAC_SHA1_32
AES_CM_192_HMAC_SHA1_32
AES_CM_128_HMAC_SHA1_32

so in this case only the below 2 match and the rest freeswitch says unsupported

AES_CM_128_HMAC_SHA1_32
AES_CM_128_HMAC_SHA1_80

the rest dont match because the placement of AES_CM_192 in FS and AES_192_CM in zoiper

may i ask why is this the case that zoiper is sending same crypto name with the text all misplaced making it impossible for FS to match and use?

 

 

于是怀疑FS和linphone的加密套件名字不匹配，然后查找log发现每次匹配上打电话的 只有AES_CM_128_HMAC_SHA1_80

然后尝试指定加密套件，结果正常！