This patch is for users who are trying to connect Asterisk to a trunk or gateway that doesn’t allow a caller-id. Normally when you set it blank, it will fill in “asterisk” as the ID.
Some providers or devices don’t allow a user in the From: field at all. In those cases, you will need a quick little patch to allow it to be blank. If a caller-id is specified on the channel, it will get passed through.
--- channels/sip/include/sip.h 2013-01-09 16:30:25.000000000 -0400 +++ channels/sip/include/sip.h 2013-06-26 13:52:03.713476705 -0300 @@ -184,7 +184,7 @@ #define DEFAULT_MOHINTERPRET "default" /*!< The default music class */ #define DEFAULT_MOHSUGGEST "" #define DEFAULT_VMEXTEN "asterisk" /*!< Default voicemail extension */ -#define DEFAULT_CALLERID "asterisk" /*!< Default caller ID */ +#define DEFAULT_CALLERID "" /*!< Default caller ID */ #define DEFAULT_MWI_FROM "" #define DEFAULT_NOTIFYMIME "application/simple-message-summary" #define DEFAULT_ALLOWGUEST TRUE --- channels/chan_sip.c 2013-06-26 13:45:36.202153235 -0300 +++ channels/chan_sip.c 2013-06-26 13:44:47.912153728 -0300 @@ -12495,9 +12495,9 @@ ourport = (p->fromdomainport) ? p->fromdomainport : ast_sockaddr_port(&p->ourip); if (!sip_standard_port(p->socket.type, ourport)) { - snprintf(from, sizeof(from), ""%s" <sip:%s@%s:%d>;tag=%s", n, tmp_l, d, ourport, p->tag); + snprintf(from, sizeof(from), ""%s" <sip:%s%s%s:%d>;tag=%s", n, tmp_l, ast_strlen_zero(tmp_l) ? "" : "@", d, ourport, p->tag); } else { - snprintf(from, sizeof(from), ""%s" <sip:%s@%s>;tag=%s", n, tmp_l, d, p->tag); + snprintf(from, sizeof(from), ""%s" <sip:%s%s%s>;tag=%s", n, tmp_l, ast_strlen_zero(tmp_l) ? "" : "@", d, p->tag); } if (!ast_strlen_zero(explicit_uri)) {