Bit-aligned header compression for CCN messages using dictionary

1. A computer-implemented method for efficient packet forwarding, the method comprising:

storing, in a storage device in a first node, a static dictionary comprising a mapping between a type and length (TL) string and a byte-aligned compressed replacement string;

encoding the byte-aligned compressed replacement string based on an encoding technique to generate a bit-aligned encoded replacement string that includes a variable length value encoded as a prefix indicating a start of a range of values and a number of bits;

storing a mapping between the encoded replacement string and the TL string in an encoded dictionary;

in response to identifying the TL string in a packet, replacing the TL string with the encoded replacement string; and

transmitting the packet to a second node storing the encoded dictionary in a local storage device, thereby facilitating bit-aligned compression of the TL string.

2. The method of claim 1 , wherein the packet is a content-centric network (CCN) message, and wherein a name for the CCN message is a hierarchically structured variable length identifier (HSVLI) which comprises contiguous name components ordered from a most general level to a most specific level;

wherein the method further comprises replacing a fixed header of the CCN message with a compressed fixed header.

3. The method of claim 1 , further comprising:

generating a compressed representation of a type, length, and value (TLV) string in response to identifying the TLV string in the packet;

storing the compressed representation for the TLV string in a learned dictionary in the storage device of the first node;

in response to identifying the TLV string in a subsequent second packet, compressing the TLV string in the second packet based on the compressed representation.

4. The method of claim 3 , further comprising, in response to not matching a TL pair of the packet in the static, encoded, and learned dictionaries, compacting the TL pair using a shorter bit length representation of a type and length of the TL pair.

5. The method of claim 3 , wherein an entry in the static, encoded, or learned dictionary includes an identifying pattern, wherein the pattern indicates to which dictionary the entry belongs.

6. The method of claim 1 , wherein the encoding is based on Huffman encoding.

7. The method of claim 6 , wherein a Huffman code represents one or more of:

a fixed type and a fixed length;

a series of TL pairs with no intermediate value;

a fixed type and a specified bit length, wherein the Huffman code is followed by a specified number of bits; and

a fixed type and a variable bit length, wherein the Huffman code is followed by the variable length value.

8. The method of claim 7 , wherein the variable bit length is calculated as a summation of the start of the range and a value represented by the number of bits.

9. A computer system for facilitating forwarding of packets, the system comprising:

a processor; and

a storage device storing instructions that when executed by the processor cause the processor to perform a method, the method comprising:

storing, in a storage device in a first node, a static dictionary comprising a mapping between a type and length (TL) string and a byte-aligned compressed replacement string;

encoding the byte-aligned compressed replacement string based on an encoding technique to generate a bit-aligned encoded replacement string that includes a variable length value encoded as a prefix indicating a start of a range of values and a number of bits;

storing a mapping between the encoded replacement string and the TL string in an encoded dictionary;

in response to identifying the TL string in a packet, replacing the TL string with the encoded replacement string; and

transmitting the packet to a second node storing the encoded dictionary in a local storage device, thereby facilitating bit-aligned compression of the TL string.

10. The computer system of claim 9 , wherein the packet is a content-centric network (CCN) message, and wherein a name for the CCN message is a hierarchically structured variable length identifier (HSVLI) which comprises contiguous name components ordered from a most general level to a most specific level;

wherein the method further comprises replacing a fixed header of the CCN message with a compressed fixed header.

11. The computer system of claim 9 , wherein the method further comprises:

generating a compressed representation of a type, length, and value (TLV) string in response to identifying the TLV string in the packet;

storing the compressed representation for the TLV string in a learned dictionary in the storage device of the first node;

in response to identifying the TLV string in a subsequent second packet, compressing the TLV string in the second packet based on the compressed representation.

12. The computer system of claim 11 , wherein the method further comprises, in response to not matching a TL pair of the packet in the static, encoded, and learned dictionaries, compacting the TL pair using a shorter bit length representation of a type and length of the TL pair.

13. The computer system of claim 11 , wherein an entry in the static, encoded, or learned dictionary includes an identifying pattern, wherein the pattern indicates to which dictionary the entry belongs.

14. The computer system of claim 9 , wherein the encoding is based on Huffman encoding.

15. The computer system of claim 14 , wherein a Huffman code represents one or more of:

a fixed type and a fixed length;

a series of TL pairs with no intermediate value;

a fixed type and a specified bit length, wherein the Huffman code is followed by a specified number of bits; and

a fixed type and a variable bit length, wherein the Huffman code is followed by the variable length value.

16. The computer system of claim 15 , wherein the variable bit length is calculated as a summation of the start of the range and a value represented by the number of bits.

17. A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method, the method comprising:

storing, in a storage device in a first node, a static dictionary comprising a mapping between a type and length (TL) string and a byte-aligned compressed replacement string;

encoding the byte-aligned compressed replacement string based on an encoding technique to generate a bit-aligned encoded replacement string that includes a variable length value encoded as a prefix indicating a start of a range of values and a number of bits;

storing a mapping between the encoded replacement string and the TL string in an encoded dictionary;

in response to identifying the TL string in a packet, replacing the TL string with the encoded replacement string; and

transmitting the packet to a second node storing the encoded dictionary in a local storage device, thereby facilitating bit-aligned compression of the TL string.

18. The storage medium of claim 17 , wherein the packet is a content-centric network (CCN) message, and wherein a name for the CCN message is a hierarchically structured variable length identifier (HSVLI) which comprises contiguous name components ordered from a most general level to a most specific level;

wherein the method further comprises replacing a fixed header of the CCN message with a compressed fixed header.

19. The storage medium of claim 17 , wherein the method further comprising:

generating a compressed representation of a type, length, and value (TLV) string in response to identifying the TLV string in the packet;

storing the compressed representation for the TLV string in a learned dictionary in the storage device of the first node;

in response to identifying the TLV string in a subsequent second packet, compressing the TLV string in the second packet based on the compressed representation.

20. The storage medium of claim 17 , wherein the encoding is based on Huffman encoding.