Docker环境中Asterisk无法注册SIP中继的问题求助

我目前正在Docker容器里搭建Asterisk，已经成功创建了SIP中继，但测试的时候发现只有发送流量，完全没有接收流量，测试时的流量情况如下：

另外附上Asterisk的相关日志，能看到注册一直超时，不断重试：

[2024-04-10 08:29:48] NOTICE[9390]: chan_sip.c:16046 sip_reg_timeout:    -- Registration for '234b80b8@sip.nexmo.com' timed out, trying again (Attempt #18)
[2024-04-10 08:30:08] NOTICE[9390]: chan_sip.c:16046 sip_reg_timeout:    -- Registration for '234b80b8@sip.nexmo.com' timed out, trying again (Attempt #19)
[2024-04-10 08:30:28] NOTICE[9390]: chan_sip.c:16046 sip_reg_timeout:    -- Registration for '234b80b8@sip.nexmo.com' timed out, trying again (Attempt #20)
[2024-04-10 08:30:48] NOTICE[9390]: chan_sip.c:16046 sip_reg_timeout:    -- Registration for '234b80b8@sip.nexmo.com' timed out, trying again (Attempt #21)
[2024-04-10 08:31:08] NOTICE[9390]: chan_sip.c:16046 sip_reg_timeout:    -- Registration for '234b80b8@sip.nexmo.com' timed out, trying again (Attempt #22)

有没有大佬能帮忙看看这是什么问题呀？已经卡了好一会儿了，谢谢大家！

备注：内容来源于stack exchange，提问作者famfamfam