R2511-HP MSR Router Series Voice Configuration Guide(V5)

156
Ste
p
Command Remarks
4. Configure the device to obtain
the destination number from
the To header field for
sending a SIP request.
sip-comp callee
By default, the destination number
is obtained from the request-line,
which is the start line in an SIP
request message.
5. Configure the device to use
the address in the To header
field as the address in the
From header field.
sip-comp from
By default, the From header field
contains the source address, and
the To header field contains the
destination address.
Enabling the number substitution function
Devices from some vendors cannot recognize the pound sign (#) in call numbers.
To communicate with such devices, enable the number substitution function so that the device replaces
the pound sign in called numbers with the ASCII code %23 for outgoing calls, and replaces the ASCII
code %23 in called numbers with a pound sign for incoming calls. Moreover, the device replaces the
pound sign in the called number with the ASCII code %23 in the Contact header field of any subsequent
request and response.
Typically, the translated called number is limited in length. If a translated called number contains more
than 31 digits, only the first 31 digits are sent. With this length limitation, the device might not replace all
pound signs in a called number. For example, the number 123456789012345678901234567##89 is
translated to 123456789012345678901234567%23.
To enable the number substitution function:
Ste
p
Command Remarks
1. Enter system view.
system-view N/A
2. Enter voice view.
voice-setup N/A
3. Enter SIP client view.
sip N/A
4. Enable the number
substitution function.
sip-comp substitute
By default, the number substitution
function is disabled.
Configuring SIP compatibility for fax pass-through and modem pass-through
When the device communicates with devices of other vendors, you can set the following options to meet
your network requirements. After the x-param compatibility option is configured:
• If the device receives a re-INVITE request with the a=X-modem field, it will reply with a 200 OK
response carrying the a=X-modem field in the SDP field.
• If the device receives a re-INVITE request with the a=X-fax field, it will reply with a 200 OK response
carrying the a=X-fax field.
• When the device initiates a fax pass-through operation, the a=X-fax field is carried in the re-INVITE
request. When the device initiates a modem pass-through operation, the a=X-modem field is
carried in the re-INVITE request.
After the T.38 compatibility option is configured, the device can recognize T.38-specific description fields,
and fax parameters T38FaxTranscodingJBIG, T38FaxTranscodingMMR, and T38FaxFillBitRemoval.
These are in the SDP fields of the re-INVITE requests and 200 OK responses, and do not contain :0.
By default, the compatibility options are not carried in re-INVITE requests. After the compatibility option
command is configured, the compatibility options will be carried in re-INVITE requests.