1. Field
Example aspects described herein relate generally to communications equipment, and more specifically to systems and apparatuses that enable a pluggable optical device to accommodate multiple communication interface types.
2. Description Of The Related Art
In today's high-technology world, data needs to be transmitted over high-speed computer networks. Optical fibers serve as good network data carriers because, in addition to being flexible and enabling signals to travel with little attenuation, they can each transmit data at a rate of at least ten gigabits (10 G) per second, often at least 40 G per second.
Signals that are communicated using optical fibers are often sent and received by pluggable optical devices. One known type of pluggable optical device is a C form-factor pluggable (CFP), which is multi-source and hot-pluggable. Another known type of pluggable optical device is a quad small form-factor pluggable plus (QSFP+), which is similar to a CFP but more compact.
Generally, pluggable optical devices of the QSFP+ type support a 40 G interface, but do not have sufficient surface area to be able to accommodate a plurality of 10 G interfaces, owing to the amount of area that would be required for the associated LC optical connectors and patch panels to accommodate such interfaces. Also, even if a break-out cable (which has been used in the prior art to support 10 G client equipment) were to be connected to the 40 G interface of a QSFP+, and 10 G fibers of the break-out cable were to be connected to 10 G client equipment externally from the QSFP+, such a configuration can suffer from fiber length mis-match issues.
The above and other limitations are overcome by an optical system that enables at least one pluggable optical device to accommodate at least one additional type of interface capability, and also by a connector system usable in the system, and the at least one pluggable optical device.
In one example embodiment herein, the optical connector system comprises a first optical connector, a plurality of second optical connectors, and a mounting system hosting at least the plurality of second optical connectors. The connector system also includes a mechanism arranged to connect the first optical connector to the plurality of second optical connectors. In one example embodiment, the mounting system is formed integrally with the at least one pluggable optical device.
The system also can include at least one further pluggable optical device having at least one optical interface optically coupled to the first optical connector.
In one example embodiment, the pluggable optical device is a CFP device, and the further pluggable optical device is a QSFP+. With this configuration, the QSFP+ can accommodate at least one of a 40 G and 10 G interface capability, thereby enabling the QSFP+ to be connectable to at least one of 40 G and 10 G client equipment.
By virtue of the above system, small form-factor pluggable (SFP+) cages and associated crosspoint are not necessary, thereby enabling costs to be reduced, and also rendering it possible to support both transponder and muxponder applications.
The teachings claimed and/or described are further described in terms of exemplary embodiments. These exemplary embodiments are described in detail with reference to the drawings. These embodiments are non-limiting exemplary embodiments, in which like reference numerals represent similar structures throughout the several views of the drawings, and wherein:
a shows a blank plate of the front panel of
b shows the plate of
It should be noted that different ones of the Figures may include the same reference numerals to identify the same components, and thus a description of each such component may not be provided herein with respect to each particular Figure.
The present application presents several novel and inventive approaches for combining the capabilities of multiple pluggable optical devices, such as optical transceivers, to enable at least one of them to accommodate at least one functional capability that it would not otherwise be able to accommodate.
As described above, generally it is difficult, if not impossible, to make pluggable optical devices of the small form-factor pluggable plus (QSFP+) type accommodate a plurality of 10 G interfaces, owing to the amount of space that would be required for the associated connectors. Thus, such QSFP+ devices generally do not operate with direct 10 G-capable connections that would be used to connect to, for example, external client equipment. However, according to an example aspect herein, a configuration is provided that enables a pluggable optical device, such as a QSFP+ optical device, to operate with such a capability.
By example only, one example embodiment herein enables a pluggable optical device, such as a QSFP+ optical device, to support at least one additional type of communication interface. More particularly, in one example embodiment a QSFP+ optical device that has the ability to support a 40 G interface, is provided with a capability to support 10 G interfaces, although the scope of the invention is not limited to either of those particular types of interfaces only. Such a QSFP+ optical device can thus be connected to at least one of 40 G and 10 G client equipment.
A communication port (e.g., a QSFP+ port) 109 is provided in the housing for QSFP+ 102, and a CFP communication port 110 is provided in the housing for CFP 105. In one example embodiment these ports each can include a mechanical cage structure, for mechanical support. The QSFP+ 102 has a communication interface (also referred to herein as an optical connector) 103, such as, for example, a 40 G interface. In one example embodiment, the CFP 105 has an integrated patch panel 108 hosting a communication interface (also referred to herein as an optical connector) 106 as well as communication interfaces (also referred to herein as optical connectors) 107. In one example embodiment, interface 106 is a 40 G interface, and interfaces 107 include four 10 G interfaces. In this context, it is understood that a 10 G interface can support data rates from 9.9 Gbps to 11.5 Gbps, and a 40 G interface can support rates from 39 Gbps to 46 Gbps. A cable 104, such as, in one example, a 40 G parallel fiber cable, is communicatively connected to the interface 103 at one end and to the interface 106 at another end, thus connecting the CFP 105 with the QSFP+ 102. It should be noted that, while the cable 104 is represented as being external to the circuit pack 111, in other embodiments it can be included within the housing 112 of the circuit pack 111.
According to an example aspect herein, the QSFP+ 102 can support interfaces, such as for example, 10 G interfaces, through the existing CFP port 110, without having to itself accommodate connectors for interfaces such as 10 G interfaces. In this manner, the circuit pack 111 can support both transponder applications with 10 G interfaces and applications with 40 G interfaces, as well as muxponder applications with the combination of the 10 G and 40 G interfaces on the QSFP+ 102 and CFP 105. For example, for “add direction” signals being added, the circuit pack 111 can be equipped to combine four 10 G signals into a single wavelength 40 G Wavelength Division Multiplexed (WDM) signal, and, for “drop direction” signals to be dropped, the circuit pack 111 can be equipped to de-multiplex four 10 G signals from a 40 G single wavelength WDM signal, although this example is non-limiting.
Referring now to
The cable 203 can be broken out into individual optical fibers 204, which are respectively coupled to the connectors 202. In particular, in one example embodiment, each connector 202 is at 10 G connector that is connected to a corresponding pair of the individual optical fibers 204, and each individual fiber of the pair is a unidirectional fiber that carries signals traveling in a direction that is opposite to the direction in which signals are carried by the other one of the fibers of the pair, such that together the pair functions bidirectionally. Of course, the scope of the invention is not limited to that configuration only, and in other embodiments, for example, single bidirectional fibers or other configurations can be employed.
In this manner, the CFP 105 has an integrated patch panel 108 which hosts various connectors, including, for example, connectors 212 and 202 (and, in one example, that configuration enables individual optical fibers 204 to be employed that have fixed, uniform lengths). By virtue of that configuration, and by connecting the CFP 105 with the QSFP+ 102 through the cable 104 as described above in connection with
Another example embodiment of a pluggable optical device, such as a CFP 306, will now be described, with reference to
For example, in the illustrated embodiment, each communication path formed by a respective one of the fibers 204 has a coupling device 304, such as a 1:N optical coupler, interposed therein (e.g., N=2 in the illustrated embodiment). At each coupling device 304, an optical signal received by the device 304 from the respective fiber 204 is split, and provided on each of the N outputs of the device 304. One version of the signal is outputted through one output of the device 304 and is forwarded to a corresponding one of connectors 202 (e.g., in one example the signal is forwarded to one connector part of a dual LC connector). A further version of the signal is provided at another output of the device 304 and is forwarded along another communication path formed by a corresponding fiber 307 to a circuit device, such as a PCB assembly 302, provided in the CFP 306.
The further version of the signal provided at the other output of each device 304 is forwarded to a corresponding optical detector 303. Each detector 303 is responsive to a received signal by detecting whether the power level of the signal meets or exceeds a predetermined power level, meaning that a signal is present on the applicable communication path formed by the components 307, 304, 204, 203, 201, 210, 212, and 104. If the predetermined power level is not met or exceeded, then no signal is deemed present in the applicable communication path, which may indicate a need for troubleshooting.
The PCB assembly 302 has one or more electrical components. In one example embodiment, the assembly 302 includes the optical detectors 303, such as, for example, a photodiode detector. The printed circuit board (PCB) assembly 302 also can include additional components such as one or more optical-to-electrical converters (and/or electrical-to-optical converters) 310, controllers 312 (e.g., one or more microprocessors and/or field-programmable arrays), communication electronics 314, one or more memories 320, one or more amplifiers (not shown), and the like.
An electrical connector 305 provided in the CFP 306 also enables the PCB assembly 302 to be attached or coupled to a control device such as a motherboard assembly 316, and/or a network control system or element. In the illustrated embodiment, assembly 316 is shown external to the CFP 306 (in one example assembly 316 is included in a housing of an optical circuit pack in which CFP 306 is housed, although this example is non-limiting).
The PCB assembly 302 can exchange information with the assembly 316. For example, PCB assembly 302 can receive from the motherboard assembly 316 various commands for monitoring the activities of the CFP 306, and the assembly 302 can process the commands and return replies to the motherboard assembly 316.
One example of a type of command provided by the assembly 316 is a query for the power level in one or more communication paths monitored by corresponding ones of the photodetectors 303. An indication of the power level detected by the applicable photodetectors 303 is provided to the controller 312 by way of converter 310, and the controller 312 responds to the command from the assembly 316 by providing an indication of the power level to the assembly 316 by way of components 314 and 305.
Another type of command is a query for a type of the pluggable optical device, such as, for example, whether the applicable device is a CFP or QSFP+, and/or whether the device is a certain type of CFP or QSFP+, and/or whether the device has transceiver capabilities. For example, the memory 320 can include an internal register which stores information representing the type of the pluggable optical device in which it resides (e.g., information indicating that device 306 is a CFP), and/or the whether the device has transceiver capabilities. The information in the internal register can thus be retrieved by controller 312 in response to it receiving the query from the motherboard assembly 316, and then the controller 312 forwards the information to the assembly 316 by way of components 314 and 305.
It should be noted that, for convenience, only one of the connectors 202 is represented in
Another example of a pluggable optical device that may form the pluggable optical device 105 of
According to an example aspect herein, by virtue of the configuration of
According to another example aspect herein, and referring now to
The blank plate 603 and the plate 901 with the patch panel assembly may be fastened (or attached) to the front panel 601 using two or more screws 604, or some similar acceptable attachment mechanism. In one embodiment, the plates 603 and 901 may contain integrated “captive screws”, preventing the need for screws that are separate entities. Such captive screws may have integrated “thumb screws” that allow the panel to be attached without the need for any type of tool, such as a screw driver or Allen wrench.
Referring now also to
It should be noted that, according to one embodiment herein, a circuit pack is provided with a patch panel integrated into the circuit pack's front panel (like that shown in
It should be noted that, although not shown in the drawings besides
The above example embodiments enable a pluggable optical device, such as a QSFP+ that has at least one 40 G interface for connecting to 40 G client equipment, to support at least one additional type of communication interface (e.g., 10 G interfaces), thereby enabling the QSFP+ to be connectable to 10 G client equipment. As a result, it is possible to support both transponder and muxponder applications using, for example, a same circuit board.
Of course, it also is within the scope of the present invention to enable one or more pluggable optical devices to accommodate more than the types of communication interfaces mentioned herein, and interfaces 103, 106, 107, 1103, 1106, 1107 may include more (or less, in the case of interfaces 107 and 1107) than the number of connectors referred to herein, and those interfaces may have other bandwidth capabilities besides 40 G and/or 10 G referred to herein. In one example embodiment, the number of connectors 202 can be another multiple of the number of interface(s) 103, 1103, besides four, or need not be any particular multiple of that number of interface(s). Also, although described in the context of pluggable optical devices, the scope of the invention is not limited only thereto, and also can encompass providing multiple interface-type accommodation for other types of devices besides pluggable optical devices.
In the above descriptions, various aspects of the invention have been described with reference to specific example embodiments. The specification and drawings are accordingly to be regarded in an illustrative rather than in a restrictive sense. It will, however, be evident that various modifications and changes may be made without departing from the broader spirit and scope of the present invention.
In addition, it should be understood that the figures illustrated in the attachments, which highlight the functionality and advantages of the present invention, are presented for example purposes only. The architecture of the example aspect of the present invention is sufficiently flexible and configurable such that it may be utilized (and navigated) in ways other than that shown in the accompanying figures.
Although example aspects of this invention have been described in certain specific embodiments, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present example embodiments, again, should be considered in all respects as illustrative and not restrictive.