Table Of Contents
Extended Simple Mail Transfer Protocol (ESMTP) Accounting in Store and Forward Fax
Related Features and Technologies
Supported Standards, MIBs, and RFCs
Extended Simple Mail Transfer Protocol (ESMTP) Accounting in Store and Forward Fax
This feature module contains information about how to implement specialized accounting services in Store and Forward Fax using Extended Simple Mail Transfer Protocol (ESMTP).
This document includes the following sections:
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Supported Standards, MIBs, and RFCs
Feature Overview
Store and Forward Fax enables Cisco AS5300 access servers to send and receive faxes across packet-based networks. With Store and Forward Fax, the Cisco AS5300, acting as the on-ramp gateway, receives faxes from end users and converts them into TIFF files. It then creates a standard Multipurpose Internet Mail Extensions (MIME) e-mail message and attaches the TIFF file to it. The on-ramp gateway then forwards this "fax-mail" to the messaging infrastructure of a designated SMTP server, where the fax-mail message is stored. The messaging infrastructure performs message routing, message storage, and transport, and can be either a standard Internet Mail Transport Agent (MTA)—for example, UNIX sendmail—or custom store-and forward fax software. The responsibility of delivering the fax-mail message falls to SMTP and the mail server.
After the fax-mail is stored on the SMTP server, it can be delivered either as an e-mail message with attachment when the recipient downloads messages or as a standard fax to a Group 3 fax device. In the latter case, the SMTP server mail delivery infrastructure delivers the fax-mail to the Cisco AS5300 acting as an off-ramp gateway. The off-ramp router converts the attached TIFF file back into standard fax format and then sends the information to a standard Group 3 fax device. The off-ramp gateway is also responsible for generating delivery status notifications (DSNs) and message disposition notifications (MDNs).
shows a simple network topology using Store and Forward Fax.
Figure 1 Topology Showing Store and Forward Fax Functionality
Store and Forward Fax functionality is facilitated through Simple Mail Transfer Protocol (SMTP). Additional functionality is provided in this product to provide confirmed delivery using existing SMTP mechanisms (such as ESMTP) for those features.
In Store and Forward Fax, you can collect accounting information about fax services in two ways:
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The ESMTP Accounting in Store and Forward Fax feature enables you to collect accounting information about fax services as part of the SMTP session. This functionality is activated through the use of an intelligent fax client or MTA. In ESMTP accounting, the off-ramp gateway (acting in its capacity as an ESMTP server) advertises capabilities to the MTA, which is acting as an e-mail client. One of the capabilities the off-ramp gateway advertises is xaccounting, which means that it supports ESMTP accounting. If the MTA recognizes the xaccounting service extension, the MTA (acting as the client) can accept the ESMTP accounting information sent from the off-ramp gateway. If the MTA does not recognize the xaccounting service extension, it will not send the xact command to the off-ramp gateway. In that case, the off-ramp gateway will not respond with ESMTP accounting data.
To use SMTP to collect accounting data, then, you must configure the MTA to explicitly request accounting information as part of the e-mail session—meaning that you must program the MTA to do the following:
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You need not configure any commands on the Cisco AS5300 to enable ESMTP accounting.
In the following example, ESMTP accounting is manually activated via a Telnet session. The output from the MTA is in bold; the output from the off-ramp Cisco AS5300 is in italics.
Note
telnet 172.14.120.2 25Trying 172.14.120.2...Connected to 1.14.120.2.Escape character is '^]'.220 mmoip-b.cisco.com Cisco NetWorks ESMTP serverehlo anyserver.com250-mmoip-b.cisco.com, hello anyserver.com [223.255.254.10] (really)250-ENHANCEDSTATUSCODES250-8BITMIME250-PIPELINING250-HELP250-DSN250-XSESSION250 XACCOUNTINGmail from:<>250 2.5.0 Sender <> okrcpt to:<FAX=+1408555-7442@cisco.com>250 2.1.5 Recipient <FAX=+1408555-7442@cisco.com> ok, maps to '5557442' (cp=yes)xact250 2.5.0 XACCOUNTING enableddata354 Enter mail, end with a single "."Testing 1 2 3Testing 1 2 3Testing 1 2 3Testing 1 2 3Testing 1 2 3Testing 1 2 3Testing 1 2 3.The following example shows the accounting information sent to the SMTP server from the off-ramp gateway when the fax transmission is successful:
250-2.5.0 Message delivered to remote fax machine250-2.5.0 fax_modem_time = 32/41250-2.5.0 fax_pages = 2250-2.5.0 gateway_id = mmoip-b.cisco.com250-2.5.0 fax_connect_speed = 14400bps250-2.5.0 transmit_bytes = 16870250-2.5.0 port_used = slot:1 port:2250-2.5.0 call_type = Fax Send250-2.5.0 abort_cause = 0250-2.5.0 T30_error_code = 0250-2.5.0 ISDN_disconnect_code = 16250 2.5.0 CSID =555-7442The following example shows the accounting information sent to the SMTP server from the off-ramp gateway when the fax transmission is unsuccessful. In this particular example, the fax transmission was unsuccessful because the line was busy.
450-4.3.2 Modem busy450-4.3.2 fax_modem_time = 0/59450-4.3.2 fax_pages = 0450-4.3.2 gateway_id = mmoip-b.cisco.com450-4.3.2 fax_connect_speed = 2400bps450-4.3.2 transmit_bytes = 0450-4.3.2 port_used = slot:1 port:3450-4.3.2 call_type = Fax Send450-4.3.2 abort_cause = 1450-4.3.2 T30_error_code = 11450-4.3.2 ISDN_disconnect_code = 17450 4.3.2 CSID =explains the example communication between the MTA and the Cisco AS5300 off-ramp gateway:
defines the ESMTP accounting information provided by the off-ramp Cisco AS5300.
explains the ESMTP mail system status codes in the previous examples.
Table 4 lists the T.30 (Rockwell Class 2) error codes used in the previous examples. Error code 0 indicates a normal connection.
Note
lists the applicable Q.931 (ISDN) call disconnection cause values. Error code 16 indicates a normal transmission.
Benefits
The ESMTP Accounting for Store and Forward Fax feature gives you another way, other than using RADIUS attributes, to collect accounting data about fax transmissions.
Restrictions
Two modem cards are available for the Cisco AS5300: the Microcom modem card and the MICA modem card. Microcom modem cards support both on-ramp and off-ramp fax activities. At the present time, MICA modem cards are unidirectional and only support off-ramp faxing. On-ramp faxing using MICA modem cards will be supported in a later release.
Related Features and Technologies
The ESMTP Accounting for Store and Forward Fax feature module is an extension to the Cisco IOS Release 12.0(4)XJ2 Store and Forward Fax feature module. The Store and Forward Fax feature module is related to the existing Voice over IP feature, which is documented in the Cisco IOS Release 12.0 Voice, Video, and Home Applications Configuration Guide and in the Cisco IOS Release 12.0(3)T feature module, titled Voice over IP for the Cisco AS5300. In addition, Store and Forward Fax uses elements from authentication, authorization, and accounting (AAA) security services, supporting the use of the RADIUS security server protocol. Store and Forward Fax also supports the use of the TACACS+ security server protocol. AAA, RADIUS, and TACACS+ are documented in the Cisco IOS Release 12.0 Security Configuration Guide.
Related Documents
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Supported Platforms
The ESMTP Accounting for Store and Forward Fax feature is supported on the Cisco AS5300 access server.
Supported Standards, MIBs, and RFCs
Standards
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MIBs
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For descriptions of supported MIBs and how to use MIBs, see the Cisco MIB web site on CCO at http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml.
RFCs
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Store and Forward Fax is also compliant with the SMTP requirements in RFC 1123, Requirements for Internet Hosts—Application and Support.
Prerequisites
You must have Store and Forward Fax configured to use ESMTP accounting. For more information about configuring Store and Forward Fax, refer to the Cisco IOS Release 12.0(4)XJ feature module titled Store and Forward Fax.
Configuration Tasks
There are no configuration tasks for the Cisco AS5300 associated with this feature.
Configuration Examples
There are no configuration examples for the Cisco AS5300 associated with this feature.
Command Reference
There are no new or modified commands associated with this feature.
Glossary
ANI—automatic number identification. Feature of Signaling System 7 (SS7) in which a series of digits, either analog or digital, are included in the call, identifying the telephone number of the calling device. In other words, ANI identifies the number of the calling party.
call leg—a discrete segment of a call connection.
CSI—called subscriber identification. An identifier whose coding format contains the telephone number from the remote fax terminal.
DID—direct inward dial. Feature that allows a user outside a company to dial an internal extension number without having to pass through an operator or attendant. The dialed digits are passed to the PBX, which then completes the call.
DNIS—dialed number identification service. Feature of trunk lines where the called number is identified; this called number information is used to route the call to the appropriate service.
DSN—delivery status notification. Message returned to the originator indicating the delivery status of an e-mail message. There are three types of delivery status notifications that can be requested by a sender: delay, success, and failure. Specifications for DSN are described in RFC 1891, RFC 1892, RFC 1893, and RFC 1894.
E.164—ITU-T recommendation for international telecommunication numbering.
ESMTP—Extended Simple Mail Transfer Protocol. Extended version of the Simple Mail Transfer Protocol (SMTP), which includes additional functionality such as delivery notification and session delivery. ESMTP is described in RFC 1869.
Group 3—standard created by the International Telecommunication Union Telecommunication standardization sector (ITU-T) relating to fax devices. A Group 3 fax device is a digital machine containing a 14400-baud modem that can send an 8.5 by 11 inch page in approximately 20 seconds with a resolution of either 203 by 98 dots per inch (dpi) or 203 by 196 dpi (fine), using Huffman code to compress fax data. Group 3 faxes use a standard dialup telephone line for transmission.
LCD—liquid crystal display. An alphanumeric display on computers and fax devices using liquid crystal sealed between two pieces of glass.
MDN—message disposition notification. Message returned to the originator of an e-mail message indicating that the e-mail message has been opened. Specifications for MDN are described in RFC 2298.
MICA—modem ISDN channel aggregation. Modem module and card used in the Cisco AS5300 universal access servers. A MICA modem provides an interface between an incoming or outgoing digital call and an ISDN telephone line; the call need not be converted to analog as it does with a conventional modem and an analog telephone line. Each line can accommodate, or aggregate, up to 24 (T1) or 30 (E1) calls.
MIME—Multipurpose Internet Mail Extension. MIME is the standard for sending non text data (or data that cannot be represented in plain ASCII code) in Internet mail, such as binary, foreign language text (such as Russian or Chinese), audio, or video data. MIME is defined in RFC 2045.
MMoIP—Multimedia Mail over Internet Protocol. Dial peer specific to Store and Forward Fax. The MMoIP dial peer is the vehicle you use to assign particular line characteristics (such as a destination telephone number) to the connection between the Cisco AS5300 access server and the SMTP mail server during on-ramp faxing.
MTA—Mail Transfer Agent. Software that implements SMTP and provides storage for mail messages to be forwarded or delivered to a local user. MTAs implement SMTP (RFC 821).
POTS dial peer—"Plain old telephone service" dial peer used as a vehicle to assign particular line characteristics to the connection between the user and the receiving Cisco AS5300 during inbound (or on-ramp) faxing and to the connection between the Cisco AS5300 access server and the receiving fax device during outbound (or off-ramp) faxing.
redialer—interface hardware device that interconnects between a fax device and a Public Switched Telephone Network (PSTN) network. A redialer is used to forward a dialed number to another destination. Redialers contain a database of referral telephone numbers. When the user dials a specific number, the redialer collects the dialed digits and matches them to a listing in its database. If there is a match, the redialer dials the referral number (transparent to the user) and forwards the call to the referral number.
SMTP—Simple Mail Transfer Protocol. Application-level protocol in the TCP/IP protocol suite involved with the transmission and reception of electronic mail. Specifications for SMTP are described in RFC 821 and RFC 822.
store and forward—function whereby a message is transmitted to some intermediate relay point and temporarily stored before forwarding to the next relay point.
TSI—transmitting subscriber information. A frame that can be sent by the caller with the telephone number of the caller that can be used to screen calls.
