WO2000033587A1

WO2000033587A1 - Call number translator

Info

Publication number: WO2000033587A1
Application number: PCT/US1999/028294
Authority: WO
Inventors: Jarrett E. Archer
Original assignee: Alcatel Usa Sourcing, L.P.
Priority date: 1998-12-01
Filing date: 1999-12-01
Publication date: 2000-06-08
Also published as: AU1927700A

Abstract

A method and system for pretranslating addressing information at a switching point in a telecommunications network includes storing address manipulation information for a plurality of pretranslate addresses at the switching point. A disparate address is generated for a received transmission having an address corresponding to one of the pretranslate addresses. The disparate address is generated by manipulating the address based on the address manipulation information for the pretranslate address.

Description

CALL NUMBER TRANSLATOR

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to the field of telecommunications, and more particularly to a method and system for pretranslating addressing information at a switching point in a telecommunications network.

BACKGROUND OF THE INVENTION

Advanced telecommunications networks include a system of trunk lines interconnected by switching points that route calls over the trunk lines. Control points are connected to the switching points in order to provide the switching points with routing and other information to support advanced services demanded by telephone users . Examples of advanced services are free phone (FPH) services such as time-dependent routing, calling card (CCD) services, and virtual private network (VPN) services.

The switching and control points are distributed in the advanced telecommunications network and connected to each other by a messaging system. Call processing relying on information from the control points is performed offline by the switching points in that such calls are held by switching points while routing information is requested and received from the remote control points over the messaging system. As a result, calls are delayed at the switching points and additional traffic is generated on the messaging system.

To reduce call processing delays, pretranslators have been employed at the switching points. The pretranslators replace called party numbers falling within specified ranges with specified numbers. Although pretranslators reduce offline call processing by providing limited intelligent routing capability at the switching points, the majority of calls requiring additional information remain dependent on offline processing.

SUMMARY OF THE INVENTION

The present invention provides an improved method and system for pretranslating addressing information in a telecommunications network that substantially reduce or eliminate disadvantages and problems associated with prior systems and methods. In particular, the present invention reduces offline call processing by providing enhanced pretranslation functionality at switching points in the telecommunications network.

In accordance with one embodiment of the present invention, a method and system for pretranslating addressing information at a switching point includes storing address manipulation information for a plurality of pretranslate addresses at the switching point. A disparate address is generated for a transmission having an address corresponding to one of the pretranslate addresses . The disparate address is generated by manipulating the address based on the address manipulation information for the pretranslate address.

More specifically, in accordance with a particular embodiment of the present invention, the switching point includes one digit pretranslate addresses, two digit pretranslate addresses, and wildcard pretranslate addresses. The address is manipulated by replacing selected digits in the address, deleting selected digits from the address, and/or inserting additional digits into the address. The manipulated digits may be at the beginning or end of the address or embedded in the address. Technical advantages of the present invention include providing an improved method and system for pretranslating addressing information in a telecommunications network. In particular, the present invention provides enhanced pretranslation functionality at switching points in the telecommunications network. The enhanced pretranslation functionality includes expanded criteria for identifying pretranslation addresses at the switching point and direct manipulation of identified addresses at the switching point. Accordingly, calls may be more intelligently routed at a switching point without resorting to offline information. This reduces delays incurred while obtaining off-line information and reduces traffic on the network messaging system.

Another technical advantage of the present invention includes providing an improved method and system for conducting proof-of-concept trials. In particular, the enhanced pretranslating functionality may be used to support advanced services in a limited testing or other suitable environment. As a result, concepts may be tested for viability in the field prior to full deployment. This greatly reduces testing cost and allows borderline concepts that could not be previously tested due to the prohibitive cost of full deployment to be tested and, if successful, later fully deployed in the field. Other technical advantages will be readily apparent to one skilled in the art from the following figures, description, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and its advantages, reference is now made to the following brief description, taken in conjunction with the accompanying drawings and detailed description, wherein like reference numerals represent like parts, in which:

FIGURE 1 is a block diagram illustrating an exemplary telecommunications network for use in connection with the present invention;

FIGURE 2 is a block diagram illustrating details of a service point for the telecommunications network of FIGURE

1;

FIGURE 3 is an exemplary illustration of the pretranslate address table of FIGURE 2 ;

FIGURE 4 is an exemplary illustration of the mechanism table of FIGURE 2;

FIGURE 5 is a flow diagram illustrating a computer method for identifying called party numbers to be pretranslated in accordance with one embodiment of the present invention; and FIGURE 6 is a flow diagram illustrating a computer method for pretranslating a called party number in accordance with one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

FIGURE 1 is a block diagram illustrating an advanced intelligent network (AIN) 10 for use in connection with the present invention. The advanced intelligent network 10 includes a service management system (SMS) 12 that interfaces with a plurality of service control points (SCP) 14 and a plurality of signal transfer points (STP) 16 via an industry standard protocol, such as X.25. The service management system 12 provides network information, database management, and administrative support for the advanced intelligent network 10. The service management system 12 generally interfaces with service control points 14 for provisioning, database management, service control point application program management, and collecting traffic metering measurement data.

The service control points 14 may be directly linked to the signal transfer points 16 via a signaling system number 7 (SS7) link set 18. The signal transfer points 16 are further coupled through signaling system number 7 link set 18 to one or more service switching points 20, which perform switching and call handling functions in the network 10. The service control points 14 are transaction- based processing systems whose primary responsibility is to respond to queries from service switching points 20 for data needed to complete the routing of a call. The service switching points 20 are part of a publicly-switched telephone network (PSTN) and are coupled to each other via trunks 22 and to telephone service subscribers, which include wire-based telephones, wireless telephones 24, and intelligent peripherals 26.

FIGURE 2 illustrates a switching point 30 for pretranslating addressing information in the advanced intelligent network 10 or other telecommunications network in accordance with one embodiment of the present invention. In this embodiment, the switching point 30 is an intermediate switch disposed between an originating agency 34 and a terminating agency 36. The originating and terminating agencies 34 and 36 are different telephony service providers operating in the same or disparate countries or regions that utilize disparate called party numbering systems. The switching point 30 provides operator-to-operator translation between the originating and terminating agencies 34 and 36 to alter digits dialed by operators of the originating agency such that the outpulse digits are acceptable to the terminating agency 36.

The switching point 30 is a Tandem switch, such as the Megahub 600E manufactured by Alcatel USA, Inc., Class 5 switch, or other suitable switch or network node capable of providing operator-to-operator translation or other types of address pretranslation in a telecommunications network. The telecommunications network may be any suitable network capable of transmitting voice, data, or a combination of voice and data or other information over a series of trunk lines or other suitable links.

The switching point 30 includes computer software and data that is loaded into system memory and executed by a microprocessor. The computer software and data are generally identified by modules, files, engines, tables, and the like. It will be understood that the computer software and data may be otherwise combined and/or divided for processing and otherwise stored in or remotely from the switching point 30 without departing from the scope of the present invention. Accordingly, the labels of the modules, files, engines, and tables are for illustrative purposes and may be suitably varied. Referring to FIGURE 2, the switching point 30 includes a pretranslator 40 having a search engine 42, a pretranslate address table 44, a manipulation engine 46, and a mechanism table 48. Generally described, the search mechanism 42 automatically searches the pretranslate address table 44 to determine whether a received address corresponds to a pretranslate address stored in the pretranslate address table 44. An event is automatic in that the event is predefined and carried out by the computer process. The event may be immediate or in response to a user action or other suitable event or action. In response to the received address corresponding to a pretranslation address, the manipulation engine 46 automatically manipulates the received address in accordance with address manipulation information stored in the mechanism table 48. The response need not be immediate nor based only on the identified event. Operation of the search and manipulation engines 42 and 46 are described in more detail below in connection with FIGURES 5 and 6. The pretranslate address table 44 stores pretranslate addresses. In one embodiment, the pretranslate address table 44 is a virtual single table that is a combination of one digit entries 50, two digit entries 52, wildcard entries 54, and range entries 56. In this embodiment, the pretranslate address table 44 may have an initial size of 1,010 entries and initially allow for 10 one digit entries 50, 100 two digit entries 52, 100 wildcard entries 54, and 800 range entries 56.

FIGURE 3 illustrates an exemplary pretranslate address table 44 in accordance with one embodiment of the present invention. In this embodiment, the one digit, two digit, wildcard, and range entries 50-56 are stored in a single table. Each entry comprises a FROM DIGITS field 60, a TO DIGITS field 62, and an INDEX field 64. The entries are stored in ascending order, with the FROM DIGITS and TO DIGITS fields 60 and 62 stored as standard telephony binary coded digits (TBCD) . One digit entries 50 are stored with the same number in the FROM DIGITS and TO DIGITS fields 60 and 62. Two digit entries 52 are stored with the same two numbers in the FROM DIGITS and TO DIGITS fields 60 and 62. Wildcard entries 54 are stored with a combination of digits and wildcard characters 66. The wildcard characters 66 indicate that no check is made for those digit positions.

Referring to FIGURE 3, exemplary one digit entries 50 include called party numbers "2" and "3". Two digit entries 52 include called party numbers "21" and "30".

Wildcard entries 54 include any called party numbers matching "212998***199" and ^»******i20" , with the * representing wildcard characters 66. The range entries 56 include called party numbers between "200" and "20998", between "2120" and "212998" and matching "20999". The one digit, two digit, wildcard, and range entries 50-56 each include an index number in the INDEX field 64 that is yielded by the search engine 42 in response to a successful match between a received called party number and an entry in the pretranslate address table 44. The index number is then used by the manipulation engine 46 to identify address manipulation information in the mechanism table 48 for manipulating the received called party number.

Returning to FIGURE 2, the mechanism table 48 provides address manipulation information for pretranslating called party numbers identified by the pretranslate address table 44. The manipulation engine 46 uses the index number yielded by the search engine 42 to identify address manipulation information in the mechanism table 48 corresponding to a called party number. The manipulation engine 46 then pretranslates the called party number by applying the address manipulation information specified by the mechanism table 48 to the called party number.

FIGURE 4 illustrates an exemplary mechanism table 48 in accordance with one embodiment of the present invention. In this embodiment, the mechanism table 48 includes an INDEX field 70, EXCEPTION CODE field 72, ROUTE LIST field 74, MASK field 76, DELETE field 78, PREFIX field 80, and APPEND field 82. The mechanism table 48 may have an initial size of 255 entries with digits specified by any of the fields 70-82 stored as standard telephony binary coded digits (TBCD) .

The INDEX field 70 is used by the manipulation engine 46 to identify address manipulation information in the mechanism table 48 corresponding to a called party number. The EXCEPTION CODE field 72 specifies an exception code, if any, for processing the call. The existence of an exception code indicates that the call will be blocked, and may provide an announcement or other information with which to provide back to the caller. The ROUTE LIST field 74 identifies a route list, if any, for routing the call. The route list identifies a trunk group or other information for a subsequent switch. The MASK field 76 specifies replacement digits, if any, to replace the called party number. This allows embedded digits between the beginning and end of the called party number to be altered. The DELETE field 78 specifies the number of digits, if any, to be deleted from the called party number. The PREFIX field 80 specifies digits, if any, to be added to the beginning of, or prefixed, the called party number. The APPEND field 82 specifies digits, if any, to be added to the end of, or appended to, the called party number. The fields 70-82 may each include a NULL entry to indicate that no processing for that field is to occur. Thus, the address manipulation information for each of the fields may specify digits with which to manipulate an address or specify a NULL for that field. Referring to FIGURE 4, exemplary entries include entries for index numbers "1", "2", and "3". For index number "1", the exception code is NULL indicating that the call will be processed, the route list is "25" indicating the trunk group with which the call will be routed, the MASK field 76 is NULL indicating that no digits of the called party number will be replaced, the DELETE field 78 is "3" indicating that the first three digits will be deleted, the PREFIX field 80 is "00" indicating that digits "00" will be prefixed to the called party number, and the APPEND field 82 is "120" indicating that digits "120" will be appended to the called party number. For index number "2", the exception code is NULL indicating that the call will be processed, the route list is "04" indicating the trunk group with which the call will be routed, and the MASK, DELETE, PREFIX and APPEND fields 76-82 are NULL indicating that the called party number will not be altered using information in these fields. For index number "5", the EXCEPTION CODE is NULL indicating that the call will be processed, the route list is "20" indicating the trunk group with which the call will be routed, the MASK field 76 s ^ιι***i60***" indicating that the fourth, fifth and sixth digits in the called party number will be replaced with the digits "160", the DELETE field 78 is NULL indicating that no digits will be deleted, the PREFIX field 80 specifies digits "01" that will be prefixed to the called party number, and the APPEND field 82 specifies digits "4545" that will be appended to the called party number. It will be understood that the mechanism table may include other or different fields for manipulating called party addresses.

FIGURE 5 is a flow diagram illustrating a computer method by which the search engine 42 identifies called party numbers to be pretranslated in accordance with one embodiment of the present invention. Referring to FIGURE 5, the method begins at step 100 in which a called party number is received by the switching point 30. Next, at decisional step 102, the pretranslator 40 determines whether the called party number is of a type that may be subject to pretranslation. In one embodiment, the call is of the type that may be subject to pretranslation where the call is received over RLT originating trunk class, the call or other message indicates that the call is an operator-to- operator address, or the call contains other suitable identifying information. If the call is not of the type that is subject to pretranslation, further processing is unnecessary and the No branch of decisional step 102 leads to the end of the process. However, if the call is of the type that may be subject to pretranslation, the Yes branch of decisional step 102 leads to decisional step 104.

At decisional step 104, the search engine 42 determines if the called party number is a one digit number. If the called party number is a one digit number, the Yes branch of decisional step 104 leads to step 106. At step 106, the search engine 42 compares the one digit called party number to one digit entries 50 in the pretranslate address table 44. Next, at decisional step 108, the search engine 42 determines if the one digit called party number matches any of the one digit pretranslate addresses 50 listed in the pretranslate address table 44. If there is a match, the Yes branch of decisional step 108 leads to step 110 in which pretranslation is performed for the one digit called party number using the index number yielded by the match. However, if a match does not exist, a pretranslation does not exist for the one digit called party number and the No branch of decisional step 108 leads to the end of the process. Thus, call processing is performed for the one digit called party number without pretranslation.

Returning to decisional step 104, if the called party number is not a one digit number, the No branch of decisional step 104 leads to decisional step 112. At decisional step 112, the search engine 42 determines if the called party number is a two digit number. If the called party number is a two digit number, the Yes branch of decisional step 112 leads to step 114. At step 114, the two digit called party number is compared to two digit entries 52 in the pretranslate address table 44. Next, at decisional step 116, the search engine 42 determines if the two digit called party address matches any of the two digit pretranslate addresses 52 listed in the pretranslate table 44. If the two digit called party number matches a two digit entry 52, the Yes branch of decisional step 116 leads to step 110 where, as previously described, pretranslation is performed for the called party address based on the match. However, if a match does not exist, a pretranslation does not exist for the two digit called party number and the No branch of decisional step 116 leads to the end of the process. Thus, call processing is performed for the two digit called party number without pretranslation . Returning to decisional step 112, if the called party number is not a two digit number, the No branch of decisional step 112 leads to step 118. At step 118, the called party number is compared to wildcard entries 54 in the pretranslate address table 44. Proceeding to decisional step 120, the search engine 42 determines if the called party number matches any of the wildcard entries 54 listed in the pretranslate address table 44. If the called party number matches a wildcard entry 54, the Yes branch of decisional step 120 leads to step 110 where, as previously described, pretranslation is performed for the called party number based on information yielded by the match. If a match does not exist, the No branch of decisional step 120 leads to step 122.

At step 122, the called party number is compared to range entries 56 in the pretranslate address table 44. Next, at decisional step 124, the search engine 42 determines if the called party number matches any of the range entries 56 in the pretranslate address table 44. If a match is found for the called party number, the Yes branch of decisional step 124 leads to step 110 where, as previously described, pretranslation is performed for the called party number based on information yielded by the match. If a match does not exist for the called party number, a pretranslation does not exist for the called party number and the No branch of decisional step 124 leads to the end of the process. Thus, call processing is performed without pretranslation of the called party number.

In this way, expanded criteria for identifying pretranslation address at the switching point is provided using one digit entries 50, two digit entries 52, and wildcard entries 54 in addition to range entries 56. Accordingly, more flexibility is provided to identify and pretranslate called party numbers.

FIGURE 6 is a flow diagram illustrating a computer method by which the manipulation engine 46 pretranslates a called party number in accordance with one embodiment of the present invention. Generally described, the manipulation engine 46 generates a disparate called party number by modifying the called party number based on address manipulation information contained within the mechanism table 48, routes the call based on any identified route list in the mechanism table 48, sends the modified called party number to the terminating agency 36, populates the billing record with the original information sent by the originating agency 34, establishes a circuit across the switch 30, and creates a billing record reflecting the call event .

Referring to FIGURE 6, the method begins at step 150 in which an index number is received in response to a match between a called party number and a pretranslate address stored in the pretranslate address table 44. The index number may be any suitable type of number or numbers, letter or letters, or other identifying characters operable to associate a called party number with address manipulation information.

Proceeding to step 152, the manipulation engine 46 identifies an entry in the mechanism table 48 associated with the called party number using the index number. Next, at decisional step 154, the manipulation engine 46 determines if the data manipulation information includes an exception code. As previously described, an exception indicates that the call will be blocked rather than processed and provides an announcement or other suitable information with which to complete call processing. If an exception code is provided, the Yes branch of decisional step 154 leads to step 156 in which the call is completed in accordance with the exception code. Step 156 leads to the end of the process. Accordingly, no pretranslation is conducted. However, if the EXCEPTION field is NULL at decisional step 154, then the call will be processed and the No branch of decisional step 154 leads to decisional step 158. At decisional step 158, the manipulation engine 46 determines if a route list is provided for processing the call. If the ROUTE LIST field 74 includes a route list, the Yes branch of decisional step 158 leads to step 160. At step 160, the route list is retrieved for later use in routing the call. Step 160 along with the No branch of decisional step 158 lead to decisional step 162.

At decisional step 162, the manipulation engine 46 determines whether a mask is provided for manipulating the called party number. If the MASK field 76 includes a mask, the Yes branch of decisional step 162 leads to step 164. At step 164, the mask is applied to the called party number. The mask includes replacement digits positioned to correspond to a location of selected digits in the address. In this way, embedded digits in the address are replaced. Step 164 along with the No branch of decisional step 162 lead to decisional step 166.

At decisional step 166, the manipulation engine 46 determines whether any digits of the called party address are to be deleted. If the DELETE field 78 includes a number, the Yes branch of decisional step 166 leads to step 168 where the number of digits specified in the DELETE field 78 are deleted. Step 168 leads to decisional step 170. Returning to decisional step 166, if the DELETE field 78 is NULL, then no digits are to be deleted and the No branch of decisional step 166 also leads to decisional step 170.

At decisional step 170, the manipulation engine 46 determines whether a prefix is to be added to the called party number based on the PREFIX field 80. If a prefix is to be added, the Yes branch of decisional step 170 leads to step 172 where digits specified in the PREFIX field 80 are added to the called party number. Step 172 leads to decisional step 174. Returning to decisional step 170, if the PREFIX field 80 is NULL, then no digits are to be added to the beginning of the called party number and the No branch of decisional step 170 also leads to decisional step 174. At decisional step 174, the manipulation engine 46 determines whether any digits are to be appended to the called party number based on the APPEND field 82. If digits are to be appended, the Yes branch of decisional step 174 leads to step 176 where digits specified by the APPEND field 82 are added to the end of the called party number. Step 176 leads to step 178. Returning to decisional step 174, if the APPEND field is NULL, then no digits are to be appended to the end of the called party number and the No branch of decisional step 174 also leads to step 178.

At step 178, the call is transmitted using the route list, if any, obtained at step 160 and the modified called party number is sent to the terminating agency 36. The altered called party number may have had digits replaced, removed or added. Accordingly, calls may be more intelligently routed at the switching point 30 without resorting to offline information from a remote source. This reduces delay in call processing and reduces traffic on the network messaging system 18. In another embodiment, the pretranslator 40 may be used to support advanced services in a limited testing or other suitable environment. In the testing embodiment, the pretranslator 40 provides information in a limited area to support proof-of-concept trials for advanced services. This allows a concept to be tested for viability in the field prior to full deployment. It will be understood that the pretranslator 40 may be otherwise deployed for use in other environments to locally manipulate and dynamically modify addresses and to intelligently route calls without resort to offline information.

Although the present invention has been described with several embodiments, various changes and modifications may be suggested to one skilled in the art. It is intended that the present invention encompass such changes and modifications as fall within the scope of the appended claims .

Claims

WHAT IS CLAIMED IS:

1. A method for pretranslating addressing information at a switching point in a telecommunications network, comprising: storing address manipulation information for a plurality of pretranslate addresses at the switching point; and in response to receiving at the switching point a transmission having an address corresponding to one of the pretranslate addresses, generating a disparate address for the transmission by manipulating the address based on the address manipulation information for the pretranslate address .

2. The method of Claim 1, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising replacing selected digits in the address with replacement digits specified by the address manipulation information for the pretranslate address.

3. The method of Claim 2, wherein the selected digits are embedded in the address.

4. The method of Claim 2, the act of replacing selected digits in the address with replacement digits specified by the address manipulation information for the pretranslate address comprising applying to the address a mask having the replacement digits positioned to correspond to a location of the selected digits in the address.

5. The method of Claim 1, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising deleting from the address selected digits specified by the address manipulation information for the pretranslate address.

6. The method of Claim 1, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising adding to the address additional digits specified by the address manipulation information for the pretranslate address.

7. The method of Claim 1, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising adding to a beginning of the address additional digits specified by the address manipulation information for the pretranslate address .

8. The method of Claim 1, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising adding to an end of the address additional digits specified by the address manipulation information for the pretranslate address.

9. The method of Claim 1, wherein the address manipulation information comprises masking, deletion, and insertion information for each of the pretranslate address, the act of manipulating the address based on the address manipulation information for the pretranslate address comprising: in response to determining the masking information includes a mask having replacement digits for selected digits in the address, applying the mask to the address to replace the selected digits in the address with the replacement digits; in response to determining the deletion information specifies selected digits in the address, deleting the selected digits from the address; and in response to determining the insertion information includes additional digits for the address, adding the additional digits to the address.

10. The method of Claim 1, further comprising determining whether the address corresponds to one of the pretranslate addresses by determining whether the address matches any of the pretranslate addresses.

11. The method of Claim 1, the act of storing address manipulation information for a plurality of pretranslate addresses comprising storing address manipulation information for one digit pretranslate addresses.

12. The method of Claim 11, further comprising in response to the transmission having a one digit address, determining whether the one digit address corresponds to one of the pretranslate addresses by determining whether the one digit address matches any of the one digit pretranslate addresses.

13. The method of Claim 1, the act of storing address manipulation information for a plurality of pretranslate addresses comprising storing address manipulation information for two digit pretranslate addresses.

14. The method of Claim 13, further comprising in response to the transmission having a two digit address, determining whether the two digit address corresponds to one of the pretranslate addresses by determining whether the two digit address matches any of the two digit pretranslate addresses.

15. The method of Claim 1, wherein the transmission is a call and the address is a called party number.

16. The method of Claim 1, the act of storing address manipulation information for a plurality of pretranslate addresses comprising storing address manipulation information for wildcard pretranslate addresses.

17. The method of Claim 16, further comprising determining whether the address corresponds to one of the pretranslate addresses by determining whether the address matches any of wildcard the pretranslate addresses.

18. A switching point for a telecommunications network, comprising: an pretranslate mechanism table storing address manipulation information for a plurality of pretranslate addresses; a transmission received from the telecommunications network, the transmission having an address corresponding to one of the pretranslate addresses; and a pre-translator operable to generate a disparate address for the transmission by manipulating the address based on the address manipulation information for the pretranslate address in the pretranslate mechanism table.

19. The switching point of Claim 18, further comprising: the pretranslate mechanism table including masking, deletion, and insertion information; and the pre-translator operable to use the masking, deletion, and insertion information to manipulate the address.

20. The switching point of Claim 18, further comprising : a pretranslate address table comprising one digit pretranslate addresses, two digit pretranslate addresses, and wildcard pretranslate addresses; and the pre-translator operable to compare the address to the pretranslate address table to determine whether the address corresponds to one of the pretranslate addresses.