1. A communication network, comprising:
(A) local communication links,
(B) a plurality of separately located central office switching systems interconnected via trunk circuits for selectively providing switched call connections between at least two of the local communication links in response to predetermined control data messages,
(C) a signaling communication system for two-way communications of said control data messages between at least said central office switching systems, said signaling communication system interconnecting the central office switching systems;
(D) a signaling gateway, separate from the central office switching systems and connected to said signaling communications system, said signaling gateway including an interface connected to a remote communications network and configured to exchange said control data messages between said remote communication network and said central office switching systems by way of said signaling communication system, and
(E) a signaling system security monitor, separate from the central office switching systems, said signaling system security monitor including a plurality of message templates corresponding to approved individual ones of said control data messages, sequences of such control data messages and informational relationships between the data contents of such data messages, said signaling system security monitor being responsive to said message templates to perform syntax and content dependent screening of said control data messages, said content dependent screening including checking appropriateness of said control data messages in context of (i) a state of the communications network and (ii) prior related messages.
2. The communications network according to claim 1 wherein said plurality of message templates are associated with a plurality of service providers.
3. The communications network according to claim 2 wherein said signaling system security monitor associates each of said control data messages with a corresponding one of said service providers and selects one or more of said message templates in response to the corresponding to one of said service providers.
4. The communications network according to claim 1 wherein said signaling system security monitor includes a memory storing sets of templates, each of said sets corresponding to control messages appropriate to particular call progress or transaction flow.
5. The communications network according to claim 4 wherein said templates define message formats, parameters and values associated with control message types selected from MTP, SCCP, ISUP, TCAP and AIN type messages.
6. The communications network according to claim 4 wherein said signaling system security monitor is configured to select from among said sets of templates in response to service provider authorization data associated with respective ones of said control data messages.
7. The communications network according to claim 1 wherein said signaling system security monitor is configured to selectively communicate and selectively modify so as to bring into conformance with expectations said control data messages between said signaling gateway and corresponding ones of said central office switching systems by way of said signaling communication system in response to said control messages satisfying criteria specified by corresponding ones of said templates.
8. The communications network according to claim 1 wherein said signaling system security monitor is configured to selectively (i) enable and inhibit said signaling gateway from exchanging and (ii) modify so as to bring into conformance with expectations said control data messages between said central office switching systems by way of said remote communication network and said signaling communication system.
9. The communications network according to claim 1 wherein said signaling system security monitor includes a memory storing states of respective ones of said central office switching systems, said signaling system security monitor responsive to said states for selecting ones of said templates.
10. The communications network according to claim 1 wherein said signaling gateway further comprises a signal protocol converter configured to convert SS7 type messages to another packet data format.
11. The communications network according to claim 10 wherein the other packet data format is an Internet Protocol (IP) format.
12. The communications network according to claim 1 wherein said signaling system security monitor is configured to monitor information contained in an MTP Layer 3 portion of said control data messages.
13. The communications network according to claim 12 wherein said information contained in said MTP Layer 3 portion of said control data messages includes (i) a destination point code, (ii) an originating point code, and (iii) a service indicator octet.
14. The communications network according to claim 12 wherein said signaling system security monitor is configured to monitor at least one of MTP, SCCP, ISUP, TCAP, and AIN messages.
15. The communications network according to claim 12 wherein said signaling system security monitor is configured to monitor a plurality of message types selected from MTP, SCCP, ISUP, TCAP, and AIN type messages.
16. The communications network according to claim 12 wherein said signaling system security monitor is configured to monitor calling and called party address parameters contained in SCCP message portions of said control data messages.
17. The communications network according to claim 16 wherein said signaling system security monitor is configured to determine if said monitored calling and called party address parameters are consistent with an authorized signaling relationship.
18. The communications network according to claim 12 wherein said signaling system security monitor is configured to monitor origination and destination point codes and calling and called party address parameters contained in the header of an SCCP message of said control data messages.
19. The communications network according to claim 12 wherein said signaling system security monitor is configured to monitor the originating and destination point code parameters contained in the MTP message portion, as well as the calling and called party address parameters found in the SCCP message portion of said control data messages and determine if a particular originating application is authorized to send a particular TCAP message to a particular destination application.
20. The communications network according to claim 1 wherein said signaling system security monitor includes a memory storing a state of said communications network.
21. The communication network according to claim 1 wherein said signaling system security monitor includes a memory storing permissible states of said communications network and said templates include data indicating allowable next one(s) of said states.
22. The communications network according to claim 1 wherein said signaling system security monitor includes a memory storing data relating call progress status with respective sets of control messages appropriate to initiate a next action consistent with a particular service.
23. The communications network according to claim 1 wherein said signaling system security monitor includes a memory storing data relating a transaction state with respective sets of control messages appropriate to initiate a next action consistent with a particular service.
24. The communications network according to claim 1 wherein said signaling system security monitor comprises a certification agent configured to exchange and maintain encryption key certificates.
25. The communications network according to claim 1 wherein said signaling system security monitor is configured to issue and decrypt digital time stamps.
26. A method of securely interfacing control links of respective communication networks, comprising the steps of:
storing a plurality of control message templates;
exchanging control data messages between a remote communication network and a plurality of switching systems via a local signaling communication system;
selecting ones of said control message templates in response to respective ones of said control messages;
determining, using said templates, if said control data messages are proper including, responsive to said message templates, performing syntax and content dependent screening of said control data messages, said content dependent screening including checking appropriateness of said control data messages in context of (i) a state of the communications network and (ii) prior related messages;
in response to said determining step, selectively communicating and selectively modifying so as to bring into conformance with expectations said control data messages between said central office switching systems;
selectively routing messages from an incoming link to an outgoing link in response to said control data messages; and
selectively generating control messages to help restore system integrity in cases where control messages are disallowed.
27. The method according to claim 26 wherein said plurality of control message templates are associated with a plurality of service providers.
28. The method according to claim 26 further comprising steps of:
associating each of said control data messages with a corresponding one of said service providers; and
selecting one or more of said message templates in response to the corresponding one of said service providers.
29. The method according to claim 26 wherein each of said templates corresponds to an appropriate one of (i) call progress flow and (ii) transaction processing protocol.
30. The method according to claim 26 wherein said templates define message formats, parameters values and relationships among messages, parameters and values associated with control message types selected from MTP, SCCP, ISUP, TCAP and AIN type messages.
31. The method according to claim 26 further comprising a step of selecting said sets of templates in response to service provider authorization data associated with respective ones of said control data messages.
32. The method according to claim 26 further including a step of selectively (i) enabling and inhibiting a signaling gateway from exchanging and (ii) modifying so as to bring into conformance with expectations said control data messages between said remote communication network and said signaling communication system.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A machine operator seat of a construction machine, comprising:
a seat surface having a front seat edge;
a backrest which is situated opposite to the front seat edge in the longitudinal direction of the seat surface; and
at least one armrest situated laterally to the seat surface, comprising:
a base part;
an arm support; and
at least one operating element, the arm support being situated in a rear area in the longitudinal direction and the at least one operating element being situated in a front area of the armrest in the longitudinal direction,
wherein the arm support is mounted via a guide device on the base part of the armrest, the guide device being implemented in such a way that the arm support is freely displaceable with respect to the base part in a predetermined longitudinal displacement range along the longitudinal direction.
2. The machine operator seat according to the claim 1, wherein the guide device comprises a linear guide.
3. The machine operator seat according to claim 1, wherein the guide device is implemented to be self-positioning in such a way that the arm support automatically moves into a starting position with respect to its positioning in the longitudinal direction in an unloaded state.
4. The machine operator seat according to claim 3, characterized in that wherein the guide device has a spring loading for the self-positioning.
5. The machine operator seat according to claim 1, wherein the guide device is implemented in such a way that the arm support is freely displaceable forward and to the rear in a predetermined range in relation to a starting position in the longitudinal direction.
6. The machine operator seat according to claim 1, wherein the guide device is implemented in such a way that the arm support is freely laterally displaceable in a predetermined lateral displacement range.
7. The machine operator seat according to claim 1, wherein the guide device comprises a sliding carriage, which is mounted so the sliding carriage is displaceable on the base part of the armrest via a friction bearing, and the arm support is situated on the sliding carriage.
8. The machine operator seat according to claim 7, wherein the sliding carriage has a guide rail, which is mounted and guided in the friction bearing.
9. The machine operator seat according to claim 8, wherein the sliding carriage has an essentially horizontally extending support plate.
10. The machine operator seat according to claim 9, wherein the support plate has a tab which is bent over toward the base part on each of the opposing sides in the longitudinal direction of the support plate, and the guide rail, which is guided in a friction bearing situated fixed in place on the base part, is situated between the two tabs.
11. The machine operator seat according to claim 10, wherein a spring guide rail, on which a restoring compression spring is situated, runs between the two tabs, at least one stop element, which is displaceable along the spring guide rail, is situated on one axial end of the restoring compression spring, and a stop is provided on the base part, which is implemented to obtain a restoring function in such a way that it fixes the stop element in relation to the base part in one displacement direction and thus causes a compression of the restoring compression spring during a longitudinal displacement of the support carriage.
12. The machine operator seat according to claim 11, wherein a stop element, which is displaceable along the spring guide rail, is situated on each of the two axial ends of the restoring compression spring, and two stops, which are situated spaced apart from one another in the longitudinal direction, are provided on the base part in such a way that the restoring function is caused starting from the starting position of the arm support in one displacement direction by stopping of one stop element against one stop and in the opposite displacement direction starting from the starting position by stopping of the other stop element against the other stop.
13. The machine operator seat according to claim 11, wherein the guide rail is implemented in such a way that the guide rail is simultaneously the spring guide rail.
14. The machine operator seat, according to claim 7, wherein the sliding carriage has at least one oblong hole for guiding a lateral adjustment movement of the arm support in relation to the base part.
15. The machine operator seat according to claim 1, wherein the guide device has at least one displacement delimitation in the form of a delimitation projection on the base part.
16. A construction machine, wherein the construction machine has a machine operator seat according to claim 1.
17. A construction machine according to claim 16, wherein the construction machine comprises one of a road miller, recycler, stabilizer, a road roller or a tandem roller.