Asterisk単体で着信を受けるための設定

プレーンなAsteriskを使用している場合は、以下のIPアドレスを有効にする必要があります:
https://multitel.net/docs/view/161/knowledgebase/list-of-ip-addresses-used-for-origination
これらのIPに対応する設定を以下に示します:
sip.conf内

[sbc-ny-01]
host=67.205.139.35
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-ny-02]
host=67.205.139.36
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-sfo-01]
host=206.189.208.231
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-sfo-02]
host=206.189.208.232
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-ca-01]
host=138.197.130.40
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-ca-02]
host=138.197.130.41
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-ca-03]
host=138.197.130.42
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-ca-04]
host=138.197.130.43
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-uk-01]
host=139.59.178.18
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-uk-02]
host=139.59.178.19
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-de-01]
host=139.59.156.181
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-de-02]
host=139.59.156.182
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-nl-01]
host=95.85.22.190
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-nl-02]
host=95.85.22.191
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-sg-01]
host=128.199.64.52
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-au-01]
host=45.32.247.20
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

[sbc-br-01]
host=35.199.100.51
dtmfmode=rfc2833
dtmf=rfc2833
type=peer
context=from-multitel
insecure=invite,port
nat=never
allow=all

extensions.conf 内:

[from-multitel]
exten=> 1234567890,1,Dial(SIP/999)

NATの問題（片方向音声、または30～45秒で通話が切断される）がある場合は、上記の各トランクの「nat」設定の値を次のように変更できます:

nat=rport,comedia