Exhibit 10.4


AMENDMENT TO
THE MASTER SERVICES AGREEMENT

BETWEEN

VONAGE NETWORK INC.

AND TELECOMMUNICATIONS SYSTEMS, INC.


WHEREAS Vonage
Network Inc. (“Vonage”) and Telecommunications Systems, Inc. (“TCS”) are
parties to the Master Services Agreement dated June 8, 2005 (the “Agreement”);


WHEREAS
effective this 26th day of May, 2006, the parties wish to modify
and amend the Agreement;


WHEREAS the
parties acknowledge that all of the definitions and terms shall have the same
meaning in this Amendment to the Agreement between Vonage and TCS (“Amendment”)
as the definitions and terms in the Agreement;


NOW THEREFORE,
for good and valuable consideration, the receipt and sufficiency of which is
acknowledged, the parties agree that the Exhibit D to the Agreement shall be
amended with the addition of a new subsection as follows:


Exhibit D TCS VoIP E9-1-1
PSAP Outreach Activities Statement of Work


4.3           Activation Incentive Plan


The price for performing
outreach tasks shall be subject to the following incentive plan:


·      If TCS
attains *% completion of the overall Vonage Line count totaling * lines by the
close of business on April 3, 2006, then the TCS incentive team shall share a
$100 pay out.


·      If TCS
attains *% completion of the overall Vonage Line count totaling * lines by the
close of business on April 10, 2006, then the TCS incentive team shall share a
$100 pay out.


·      If TCS
attains *% completion of the overall Vonage Line count totaling * lines by the
close of business on April 10, 2006, then the TCS incentive team shall share a
$100 pay out.


This will be for a
maximum of $* per payout level.


IN WITNESS WHEREOF, the
parties have executed this Amendment as of the date first written above.


	
  VONAGE NETWORK INC.

  	
  TELECOMMUNICATIONS SYSTEMS, INC.

  
	
   

  	
   

  	
   

  	
   

  
	
  By:

  	
  /s/ LOUIS
  MAMAKOS

  	
   

  	
  By:

  	
  /s/ RICHARD A.
  YOUNG

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Print Name: 

  	
  Louis Mamakos

  	
   

  	
  Print Name:

  	
  Richard A. Young

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  	
   

  
	
  Title: 

  	
  President

  	
   

  	
  Title:

  	
  Executive Vice President & COO

  	
   

  
												



 


*       Pages where
confidential treatment has been requested are stamped, “Confidential treatment
has been requested.  The redacted
material has been separately filed with the Commission.”  All redacted material has been marked by an
asterisk (*).









 



[VONAGE LETTERHEAD]


November 2, 2006


VIA FAX AND OVERNIGHT MAIL


TeleCommunication Systems, Inc.

275 West Street

Annapolis, MD 21401

Attn: Celeste Ciecierski


Dear Ms. Ciecierski


An administrative
error has come to our attention regarding the naming of recent amendments to
the Master Sales Agreement between TeleCommunication Systems, Inc. (“TCS”) and
Vonage Network Inc. (“Vonage”) dated June 8, 2005 (the “Agreement”).  Specifically, our files contain the following
amendments to the Agreement:


·              “Amendment to
the Master Services Agreement Between Vonage Network Inc. and
TeleCommunications Systems, Inc.”; and


·              “Amendment #1
to the Master Sales Agreement Between Vonage Network Inc. and
TeleCommunications Systems, Inc.”.


This confirms that the respective documents should
correctly be identified and referred to as:


·              “Amendment #1
to the Master Sales Agreement Between Vonage Network Inc. and TeleCommunication
Systems, Inc.”; and


·              “Amendment #2
to the Master Sales Agreement Between Vonage Network Inc. and TeleCommunication
Systems, Inc.”.


In addition, any and
all references to “Master Services Agreement” under new
Amendment #1 shall hereafter be read to mean “Master Sales Agreement,” and any
references to “Amendment” shall be read to mean “Amendment #1.”  Similarly, any and all references to
“Amendment #1” under new Amendment
#2 shall hereafter be read to mean “Amendment #2.”  References to “TeleCommunications Systems,
Inc.” shall hereafter be read to mean “TeleCommunication Systems, Inc.”
throughout both documents.


If you have any
questions, please do not hesitate to contact me directly at 732.231.6237.  Thank you for your attention to this matter.


	
  

  	
  Sincerely,

  
	
   

  	
   

  
	
   

  	
  VONAGE NETWORKS
  INC.

  
	
   

  	
   

  
	
   

  	
  /s/ ED MULLIGAN
  by Marilyn Picot

  
	
   

  	
  Ed Mulligan

  
	
   

  	
  Vice President -
  Carrier Operations

  



 


 


 


	
  ACCEPTED AND AGREED:

  	
   

  
	
   

  	
   

  
	
   

  	
   

  
	
  By:

  	
  /s/ A. CELESTE
  CIECIERSKI

  	
   

  
	
   

  	
   

  	
   

  
	
  Name:

  	
  A. Celeste
  Ciecierski

  	
   

  
	
   

  	
   

  	
   

  
	
  Title:

  	
  Director of
  Contracts

  	
   

  



 


cc:                                 Dave
Rao

Joe Brucchieri

Zenas Choi